Abstract: Additive manufacturing (AM) is a flexible technology allowing designers to produce highly customized and complex shapes. The design phase can be supported by Design for AM (DfAM) tools in order to reduce material waste, design time and economic resources. This paper aims to evaluate the functionality of four commercial tools for simulating the powder bed fusion (PBF) deposition process using quantitative and qualitative evaluation metrics. An AM process simulation workflow has been defined to facilitate the tools evaluation. For a complete evaluation, three different case studies were analyzed. Simulation carried out with the tools have the same critical zones relative to the three mechanical components, but with different maximum distortion values. Qualitative metrics show differences in workflow complexity and support provided by tools during the simulation setup phase. In the industrial field, these aspects can affect the choice of one tool over another.

Keywords: Additive Manufacturing | Design for Additive Manufacturing | DfAM tools | PBF deposition process | Simulation

Abstract: Recent scientific studies are targeted at applying and assessing the effectiveness of Machine Learning (ML) approaches for cost estimation during the preliminary design phases. To train ML prediction models, comprehensive and structured datasets of historical data are required. This solution is inapplicable when such information is unavailable or sparse due to the lack of structured datasets. For engineered-to-order products, the number of historical records is often limited and strongly influenced by different purchasing or manufacturing strategies, thus requiring complex normalisation of such data. This method overcomes the above limitations by presenting an ML-based cost modelling methodology for the conceptual design that is applicable even when historical data are insufficient to train the prediction algorithms. The training dataset is generated through an analytical and automatic software tool for manufacturing cost estimation. Such a tool, starting from a 3D model of a product, can quickly and autonomously assess the related cost in different scenarios. An extensive and structured training dataset can be easily generated. The proposed methodology was based on CRISP-DM (Cross Industry Standard Process for Data Mining). Cost engineers of an Oil & Gas company used the method to develop parametric cost models for discs and spacers of an axial compressor. The solution guarantees lower error (7% vs 9%) and significant time-saving (minutes instead of hours) than estimations based on other approaches. Cost models are more comprehensive (capable of analysing different scenarios), explainable (not conceived as a black box), and self-learning (can be updated by extending the training dataset).

Keywords: Conceptual costing | Conceptual design | Cost engineering | Cost estimation | Design to cost | Machine learning

Abstract: (1) Background: Traditional gait assessment methods have limitations like time-consuming procedures, the requirement of skilled personnel, soft tissue artifacts, and high costs. Various 3D time scanning techniques are emerging to overcome these issues. This study compares a 3D temporal scanning system (Move4D) with an inertial motion capture system (Xsens) to evaluate their reliability and accuracy in assessing gait spatiotemporal parameters and joint kinematics. (2) Methods: This study included 13 healthy people and one hemiplegic patient, and it examined stance time, swing time, cycle time, and stride length. Statistical analysis included paired samples t-test, Bland–Altman plot, and the intraclass correlation coefficient (ICC). (3) Results: A high degree of agreement and no significant difference (p > 0.05) between the two measurement systems have been found for stance time, swing time, and cycle time. Evaluation of stride length shows a significant difference (p < 0.05) between Xsens and Move4D. The highest root-mean-square error (RMSE) was found in hip flexion/extension (RMSE = 10.99°); (4) Conclusions: The present work demonstrated that the system Move4D can estimate gait spatiotemporal parameters (gait phases duration and cycle time) and joint angles with reliability and accuracy comparable to Xsens. This study allows further innovative research using 4D (3D over time) scanning for quantitative gait assessment in clinical practice.

Keywords: 4D scanning | gait spatiotemporal parameters | wearable mocap system

Abstract: Controls and prevention activities for musculoskeletal disorders are increasingly encouraged in the industrial context. Several ergonomic assessment techniques exist. However, they primarily focus on the biomechanical and postural load requirements of job tasks and rely on self-report and observational methods rather than direct measurements, which are often too intrusive. This study investigates whether a commercially available low-intrusive and low-cost wearable sensor can be utilised to assess muscular effort and fatigue, thereby improving decision-making in work and workstation design. For this purpose, the potential of the Myo™ armband has been explored. The electrical activity of the upper limbs (arm and forearm) was evaluated through 15 physically tasks (manual handling and assembly) conducted in laboratory conditions. Satisfactory results were obtained from the correlation and significance analysis, considering the EMG signal, the Borg scale, and the activity level (e.g., load, distance, n° of repetitions). Further experimentation was conducted to validate the proposed approach in a real production facility.

Keywords: Electromyography | Human-centered manufacturing | Muscle effort and fatigue | Physical ergonomics | Upper limbs | Work-related musculoskeletal disorders

Abstract: Background and objective: In the literature, no studies correlate the effects of mandibular advancement devices (MADs) with different titration systems to periodontitis. Through a finite element analysis (FEA), this study investigates the effects generated on periodontal ligaments (PDLs) and teeth by four commercial MADs in periodontal health and with 15% bone resorption. Methods: Four MADs (Somnodent Flex™, Somnodent Avant™, Orthoapnea™, and Herbst™) were digitalised starting from the impressions of a patient's dental arches. A force of 11.18 N, representing an advancement of 9.5 mm, was applied, and a FEA was subsequently performed. After measuring the stresses and displacements on the PDLs and teeth in healthy periodontal conditions, the vertical dimension of the alveolar bone was reduced by 15%, and measurements were repeated. Results: In terms of PDL stress, Herbst™ is the device which guarantees a more uniform increment in case of the first stage of periodontitis (+7% for mandibular and maxillary PDLs compared to the healthy condition). For Somnodent™ devices, the PDLs stress increment is almost null for mandibular PDLs but much higher than Herbst™ for maxillary PDLs (+17% and +21% for Flex™ and Avant™). Orthoapnea™ determines a PDL stress augmentation between the other devices (+16% and +7%, respectively, for maxillary and mandibular PDLs). Concerning teeth movement, Herbst™ and Orthoapnea™ determine a lower and more uniform displacement than Somnodent devices. Conclusions: The stress distribution and teeth displacement are strictly related to MAD geometry. Since its minor effects on teeth and PDLs, the Herbst™ could be more appropriate in patients with periodontitis.

Keywords: Finite element analysis | Finite element method | Mandibular advancement device | Obstructive sleep apnoea | Periodontal disease | Periodontal stress

Abstract: Objective: The study aims to evaluate the stresses and the deformations generated at the periodontal level by two mandibular advancement devices (MADs) using finite element analysis. Methods: A three-dimensional digital model of the skull of a 29-year-old patient was created using a CBCT. The 3D models of two MADs (Somnodent FlexTM and Somnodent AvantTM) were reconstructed from scanning prototypes based on the patient’s anatomy. The overall geometry was imported into software for the finite element study. A force of 11.18 N representing an advancement of 9.5 mm was applied to the devices. A finite element analysis wfas subsequently performed. Results: Somnodent FlexTM generates a peak of 3.27 kPa on periodontal ligaments and 287 kPa on teeth. For Somnodent AvantTM the maximum stress is 4.53 kPa on periodontal ligaments and 467 kPa on teeth. Conclusion: Different activation mechanisms of the devices generate stresses of different entities.

Keywords: finite element analysis | mandibular advancement device | Obstructive sleep apnea | periodontal ligaments

Abstract: The growing use of additive manufacturing (AM) processes pushes research towards studying methods to reduce their environmental impact. The part build orientation is a significant process variable, which can be chosen through the Energy Performance Assessment (EPA), a straightforward method. The paper presents a method for identifying the best part build orientation considering energy consumption. The EPA has been adapted for this purpose, resulting in an approach based on four steps. The method was employed to determine the best printing direction for three parts and two AM technologies.

Keywords: 3D printing | additive manufacturing | ecodesign | energy efficiency | sustainable design

Abstract: Metal material extrusion is a family of metal additive manufacturing that includes atomic diffusion additive manufacturing (ADAM) and bound metal deposition (BMD). In the literature, there are just a few cost models for ADAM and no one for BMD. The paper presents an analytic cost model for BMD. It considers the entire process: pre-processing, printing and post-processing. The total manufacturing cost is split into material, machine, labour, energy and consumables items. The cost model validation on a 3D-printed part determined an accuracy of 98%.

Keywords: additive manufacturing | cost estimation | design costing | design to cost | metal material extrusion

Abstract: Extended Reality (XR) applications require Photorealistic Virtual Prototypes (PVPs), usually obtained by generating a polygon-based textured model of the original CAD (Computer Aided Design). Getting PVPs requires specific rendering and texturing software tools that experienced technicians use. Automatic simplification and conversion approaches from CAD to XR exist but are almost all focused on models without textures. The paper aims to establish a semi-automatic method for creating low-poly PVPs for XR starting from 3D CAD models. The process, implemented in Blender, consists of several steps. First, starting from a high-poly model imported from a 3D mechanical CAD system, the modelling cage (a low-poly simplified version) is designed. Second, a low-poly variety of the CAD geometries are generated using Blender modifiers (i.e., shrinkwrap, subdivision surface and Boolean). Texture mapping is carried out on the cage. Then, by combining Shrinkwrap, Boolean and Subdivision Surface modifiers, the cage is projected on the CAD-imported high-poly model. Thus, it becomes a low-poly version of the same geometry. Finally, the Normal Baking process adds high-frequency details (e.g., engravings). Thanks to the generation of a UV-Mapped cage wrapping up the component, in case of local modifications to the latter, Blender semi-automatically updates the PVP. The method was used on three stock versions of a sporting rifle. With an average duration of 23 min, the proposed approach more than halved the time required with manual modelling techniques.

Keywords: 3D Modelling | Extended Reality | Texture Mapping | Virtual Prototyping

Abstract: Obstructive Sleep Apnea (OSA) is a nocturnal respiratory disorder characterised by recurrent episodes of partial or total obstruction of the upper airways due to the collapse of the pharyngeal tissue. Mandibular Advancement Devices (MADs) restore regular breathing during sleep by advancing the lower jaw in a controlled way to increase the upper airway volume. However, the relaxation of muscle tone that naturally occurs during sleep induces a vertical mouth opening that impairs the efficacy of the treatment. Thus, elastic bands are recommended to keep the mouth firmly closed. Despite successfully treating OSA, inadequate evidence exists about the effects of MADs supported by elastic bands on teeth and Periodontal Ligaments (PDLs). This study aims to develop a numerical simulation approach through the finite element method to evaluate the behaviour and the effects (displacement and stress fields) of MADs embedded with intermaxillary elastics on PDLs and teeth of patients suffering from OSA. Findings confirm the efficacy of elastics in controlling the mouth opening and reveal a stress increase at the anchorage regions. Thus, their use should be advised to patients who do not suffer from periodontal problems in the anterior region of the mouth.

Keywords: Biomechanics | Finite Element Method | Obstructive Sleep Apnea | Oral Appliance | Teeth Displacement

Abstract: Machine Learning (ML), part of Artificial Intelligence, is one of the enabling technologies of Industry 4.0. ML appears to be an effective, affordable, accurate and scalable technique to cost mechanical parts in the early stage of the design process. Despite the cost estimation methods proposed in the literature, their application in specific real industrial contexts (e.g., engineered-to-order products) is minimal. This paper presents an innovative method for developing ML-based parametric cost models. The training data set is generated thanks to an analytical and automatic software tool for cost estimation. The data is subsequently processed using the Cross Industry Standard Process for Data Mining – CRISP-DM method. CRISP-DM is a process model for data science and representation. It provides an overview of the data mining life cycle. Its flexibility and easy customisation allow the creation of a data mining model that fits the goal of this work. The proposed method was employed to develop two cost models (semi-finishing and finishing phases) for components (disks) of a gas turbine. Gradient Boosted Trees turned out to be the best-performing prediction algorithm. Design engineers successfully used the generated cost models while configuring the gas-turbine cross-section.

Keywords: Conceptual Design | Cost Estimation | Design to Cost | Industry 4.0 | Machine Learning

Abstract: In Industry 4.0, companies must focus on human-centred design for a competitive edge. The 4USER project aims to establish a user-centred design method using an interactive Photorealistic Virtual Prototype (PVP) based on Extended Reality (XR) technology, objectifying customer requirements into technical specifications. The PVP overcomes limitations associated with traditional physical prototypes, serving as a quality benchmark for final products. The research focuses on a case study involving the development of sports rifles, emphasising the importance of aesthetic quality. The proposed semi-automatic process in Blender enables the generation of low-poly PVPs, incorporating hyper-realistic textures and high-frequency details. In particular, the overall process is composed of the following steps: i) wooden texture generation via the Wasserstein Generative Adversarial Network (WGAN); ii) model creation based on a low poly “Shrinkwrap Cage”; iii) integration of generated textures into the UV-mapped model. This approach accelerates the product development cycle, reduces costs, and facilitates efficient quality control.

Keywords: 3D Modelling | Generative Model | Texture Mapping | Virtual Prototyping

Abstract: Additive manufacturing (AM) is currently one of the most promising industrial technologies that allow designers to operate with more degrees of freedom to create shapes without overthinking restrictive manufacturing constraints. Products must be conceived with the “AM on mind” to exploit AM potentialities. Design for AM (DfAM) methods and tools, such as topology optimization and generative design, are crucial for this aim. The present paper aims to understand how existing DfAM tools can effectively support the DfAM process. The study is based on the definition and application of a systematic evaluation protocol consisting of quantitative and qualitative metrics. The case studies involved four commercial DfAM tools tested on three mechanical components. Results confirmed that most of the tools lead to very similar solutions from the technical point of view since they are based on analogous optimization algorithms. The consideration of manufacturability constraints and the availability of advanced functionalities for geometry reconstruction after the optimization phase are relevant issues observed. Finally, regarding tools functionalities, notable differences have been registered

Keywords: Additive manufacturing | Design for Additive Manufacturing | DfAM tools | Generative design | Topology optimization

Abstract: Laser-Directed Energy Deposition (L-DED) is an Additive Manufacturing process in which focused thermal energy is used to fuse powder feedstock. The scientific literature concerning L-DED and cost estimation is not as comprehensive as Laser-powder Bed Fusion (L-PBF). Indeed, a robust and reliable cost model (in terms of the number of materials, machines, and process parameters managed) is not available. The paper aims to define an analytical cost model for L-DED, considering the material, machine, labour, consumables, energy and equipment cost items. The model seeks to evaluate the production cost from the machine setup to the removal of the part. Post-processing steps are not included. The cost model is based on a scientific review of journal papers, handbooks and datasheets from industrial partners. The cost drivers for this model are the overall 3-dimensions of the part, volume, material, accuracy and number of components in the build plate. The meaningful process parameters are the layer thickness, melt pool width and overlap, powder efficiency, laser power, linear energy density, scanning speed, and machine dimensions. The developed cost model was tested on two products: a heat exchanger and a landing gear analyzed in previous works. The comparison led to a deviation of about 10% for the manufacturing cost and printing time.

Keywords: Additive manufacturing | Cost model | Design to cost | Laser-directed energy deposition | Sensitivity analysis

Abstract: The orbital walls and floor are common sites of facial bone fracture and may cause severe functional impairment. The complex geometry of the bony orbit makes anatomical reconstruction extremely challenging, with main issues related to the implant’s correct shaping, positioning, and orientation inside the orbital cavity. This study proposes an innovative medical device to place patient-specific implants in fractured eye sockets properly. The device must be used with the developed improved version of a tailored implant shaping mould. The design of the orbital implant positioner followed specific clinical and technical requirements and specifications investigated through the Quality Function Deployment method. The device has been conceived to be simple, economical, capable of managing deantigenated bones or titanium meshes for orbital floor and wall, and reusable multiple times. The positioner consists of two handles hinged together and adequately coupled by a spring to allow the grasping and placing of the implant. Positioner and mould have been manufactured in polyamide using the Selective Laser Sintering technique. The system accuracy assessment resulted in promising outcomes. The mould can precisely shape the implant with a lower than 0.1 mm deviation. The implant positioner can place the implant with a rotation angle around the orbital rim of barely 7.1° and 1.2 mm deviation in the mediolateral direction (no deviations in the anteroposterior and superior-inferior directions occur)

Keywords: Computer-aided design | Craniomaxillofacial surgery | Implant design | Medical devices | Rapid prototyping

Abstract: In response to rapid population ageing, digital technology represents the greatest resource in supporting the implementation of active and healthy ageing principles at clinical and service levels. However, digital information platforms that deliver coordinated health and social care services for older people to cover their needs comprehensively and adequately are still not widespread. The present work is part of a project that focuses on creating a new personalised healthcare and social assistance model to enhance older people’s quality of life. This model aims to prevent acute events to favour the elderly staying healthy in their own home while reducing hospitalisations. In this context, the prompt identification of criticalities and vulnerabilities through ICT devices and services is crucial. According to the human-centred care vision, this paper proposes a decision-support algorithm for the automatic and patient-specific assignment of tailored sets of devices and local services based on adults’ health and social needs. This decision-support tool, which uses a tree-like model, contains conditional control statements. Using sequences of binary divisions drives the assignation of products and services to each user. Based on many predictive factors of frailty, the algorithm aims to be efficient and time-effective. This goal is achieved by adequately combining specific features, thresholds, and constraints related to the ICT devices and patients’ characteristics. The validation was carried out on 50 participants. To test the algorithm, its output was compared to clinicians’ decisions during the multidimensional evaluation. The algorithm reported a high sensitivity (96% for fall monitoring and 93% for cardiac tracking) and a lower specificity (60% for fall monitoring and 27% for cardiac monitoring). Results highlight the preventive and protective behaviour of the algorithm.

Keywords: decision-support algorithm | digital health | elderly | healthy ageing | personalised care | wearable sensors

Abstract: 3D digitisation is essential to enhance knowledge and conservation processes for Cultural Heritage (CH). However, movable heritage collected in museums, e.g., archeological finds, statues, coins, and musical instruments, often consists of highly reflective surfaces and/or featureless textures. The aim of this work is to stress the Structure from Motion Dense MultiView Reconstruction (SfM-DMVR) of objects, whose optical properties are challenging to this image-based technique. To improve the results obtained by SfM-DMVR standard acquisition workflow, this study exploited the potential of combining Noise Function Pattern (NFP) projection and light Cross Polarization (CP). Moreover, High Dynamic Range (HDR) image reconstruction was tested on images acquired according to different CP angles. The SfM-DMVR of a texture-less shiny ceramic object was then compared to the one obtained by a structured light triangulation scanner, the most reliable tool for such surfaces, but unfortunately quite expensive. The advantages and limitations of the presented method are discussed.

Keywords: 3D reconstruction | Cross polarization | Featureless surface | HDR blending | Pattern projection | Reflective surface

Abstract: Approximately 10% of hospitalized patients develops decubitus ulcers that quickly degenerates into chronic illness that reduces the quality of life and requires expensive clinical management. The use of an anti-decubitus active mattress, that automatically redistributes the pressure loads, reduces the occurrence of new lesions and promotes the healing of the pre-existing ones. The aim of this work is to design and develop two tools to support the design of an anti-decubitus active mattress. Almost all the systems found in literature are based on the classification of pressure maps through machine learning and are difficultly usable in the design context. This work proposes a pressure map Classifier and an Interactive Simulator of the mattress, based on a simpler logic, by integrating image processing techniques and functioning simulations. The Classifier can recognize the patient's pressure maps and classify them according to six reference sleep postures. The Interactive Simulator allows to understand the operating mechanisms of the mattress and to test the controller and the various control logics in the absence of a physical prototype.

Keywords: Active Anti-decubitus Mattress | Images Classifier | New product development | Simulation | User centred design

Abstract: The part build orientation is a manufacturing variable that must be considered when designing a product to maximise AM opportunities. There are several approaches to selecting the best print direction in the scientific literature by considering different criteria. However, most of the studies are focused on specific AM technologies. It is missing a general method that evaluates a widespread number of criteria. Furthermore, such approaches expect designers establish weights for technical criteria that are too specific, especially during the preliminary design steps. Designers are familiar with criteria like cost-effectiveness, productiveness, quality and mechanical strength. The paper presents a multi-criteria decision-making approach to optimise the build part orientation in additive manufacturing. The method considers five decision-making criteria (cost-effectiveness, rapidity, productiveness, quality and mechanical strength) and seventeen specific technical criteria. TOPSIS is the method used to optimise the build part orientation. A case study of three components exemplifies the five steps of the procedure.

Keywords: Additive Manufacturing | Build Part Orientation | Decision making | Design for Additive Manufacturing (DfAM) | TOPSIS

Abstract: Machine learning (ML) is a well-established research topic in Industry 4.0 is boosting its adoption. ML is also used for manufacturing cost estimation during design. Such approaches are commonly used to estimate the cost of mass-produced parts. Many consolidated historical data are available for training the regression models. Unfortunately, very often, such a database of data is not available. The paper defines an ML approach for parametric cost estimation of axisymmetric components. The data for training the ML model derives from automatic software for analytically estimating the manufacturing cost. With a proper set of simulations, the tool can generate a large amount of data for training. The paper presents the steps for developing a parametric cost model using ML. The approach is based on CRoss Industry Standard Process for Data Mining method. The proposed method was used to develop one cost model (to estimate the total cost that considered raw material and manufacturing cost). The obtained Relative Error is 23.52% ± 1.37%, coherent with E2516 - 11, Standard Classification for Cost Estimate Classification System.

Keywords: Big data | Conceptual design | Design costing | Machine learning

Abstract: Craniomaxillofacial surgeries are performed using custom-made physical cutting guides and resin dental splints that present several drawbacks (e.g. time and cost required for their design and production). The literature commonly provides augmented/mixed reality (AR/MR) solutions for assisting maxillofacial osteotomies and repositioning without any interactive guide. This work proposes a new MR application, useful for osteotomy and repositioning, providing interactive, fast, and intuitive feedback to the surgeon, who is then supported in performing the bone fragment resection and replacement frame by frame. The proposed application speeds up the surgery and reduces under/overshooting errors. Moreover, the idea of integrating osteotomy and repositioning assistance in the same MR application is rarely found in the literature. It is an entirely novel approach to craniomaxillofacial surgery. The MR application has been designed with a three-button menu. The “App Start” calibrates the app, the “Osteotomy Mode” visualises the holograms of the cutting lines and drilling points, and the “Repositioning Mode” visualises the step-by-step real-time feedback to precisely support the surgeon placing the osteotomised bone fragment towards the final pre-planned position. The MR app has been developed in Unity and deployed on Microsoft HoloLens V2. A laboratory test bench was realised to validate the accuracy of the proposed MR-based approach. The validation protocol consists of two tasks to test the osteotomy and repositioning modes using a 3D-printed skull phantom. For osteotomy, the accuracy is 0.89 mm (genioplasty), 1.24 mm (maxillary osteotomy), 1.33 mm (orthognathic surgery), and 2.89 mm (mandibular angle osteotomy). For repositioning, the accuracy is 0.6 mm (anteroposterior deviation), 0.7 mm (mediolateral deviation), and 0.6° (angular deviation).

Keywords: Augmented reality | Hololens | Maxillofacial surgery | Mixed reality | Surgical guide

Abstract: Additive manufacturing (AM) is rapidly gaining popularity and is used to create finished goods or moulds (rapid tooling). AM is also frequently employed for generating patterns and moulds, often in conjunction with casting to produce massive metal components to overcome the drawbacks of casting techniques. Compared to wax injection, Rapid Investment Casting (RIC), which is the application of AM in Investment Casting, may guarantee a significant reduction in lead time. Given the innovative nature of this technology, the scientific literature lacks in providing techno-economic evaluations concerning adopting Digital Light Processing (DLP) technologies for RIC. This study examines the techno-economic implications of using additive manufacturing (i.e., DLP) to create wax or resin models. The article provides a decision-making tool to help stakeholders assess AM’s benefits for manufacturing wax patterns instead of wax injection. Analytical cost models are provided for estimating the manufacturing time and cost of the compared technologies. The study considered two production scenarios distinguished by the machine load factor for DLP (10% and 50%). Mainly, the technology comparisons are based on production costs and times. The study takes into account parts from the fashion and mechanical sectors. Results indicate that AM is faster and cheaper than injection moulding for production batches up to 10E2 (as an order of magnitude) for small-size components and 10E1 for large parts. This outcome derives from the avoided cost for the moulds required for the injection process. Regarding cost and time, the batch cross-over points decrease when the dimensions of components are increased.

Keywords: 3D printing | Cost estimation | Investment casting | Techno-economic analysis | Vat photopolimerisation | VPP

Abstract: In hip arthroplasty, preoperative planning is fundamental to reaching a successful surgery. Nowadays, several software tools for computed tomography (CT) image processing are available. However, research studies comparing segmentation tools for hip surgery planning for patients affected by osteoarthritic diseases or osteoporotic fractures are still lacking. The present work compares three different software from the geometric, dimensional, and usability perspectives to identify the best three-dimensional (3D) modelling tool for the reconstruction of pathological femoral heads. Syngo.via Frontier (by Siemens Healthcare) is a medical image reading and post-processing software that allows low-skilled operators to produce prototypes. Materialise (by Mimics) is a commercial medical modelling software. 3D Slicer (by slicer.org) is an open-source development platform used in medical and biomedical fields. The 3D models reconstructed starting from the in vivo CT images of the pathological femoral head are compared with the geometries obtained from the laser scan of the in vitro bony specimens. The results show that Mimics and 3D Slicer are better for dimensional and geometric accuracy in the 3D reconstruction, while syngo.via Frontier is the easiest to use in the hospital setting.

Keywords: bio-imaging | CT image segmentation | hip surgery | orthopaedics | reverse engineering | software comparison | surgical planning

Abstract: Design for AM (DfAM) requires the definition of Design Actions (DAs) to optimize AM manufacturing processes. However, AM understanding is still very blurred. Often designers are challenged by selecting the right design parameters. A method to list and collect DfAM DAs is currently missing. The paper aims at providing a framework to collect DfAM DAs according to a developed ontology to create databases (DBs). DBs were tested with two real case studies and geometric features to improve identified. Future developments aim at widening the database to provide all-around support for AM processes.

Keywords: computer-aided design (CAD) | design for additive manufacturing (DfAM) | knowledge-based engineering (KBE) | ontology

Abstract: Laser Powder Bed Fusion is the most widespread additive manufacturing process for metals. In literature, there are several analytical models for estimating the manufacturing cost. However, few papers present sensitivity analyses for evaluating the most relevant product and process parameters on the production cost. This paper presents a cost model elaborated from previous studies used in a sensitivity analysis. The most relevant process parameters observed in the sensitivity analysis are the 3D printer load factor, layer thickness, raw material price and laser speed.

Keywords: additive manufacturing | cost estimation | design costing | design to x (DtX) | sensitivity analysis

Abstract: Industry 4.0 (I4.0), through the digitalization and interconnection of manufacturing processes, can offer opportunities to improve production systems' sustainability. Despite the increasing number of scientific review papers related to I4.0 and production sustainability, most approaches and tools for sustainability evaluation lack of a tangible implementation framework. The paper presents a framework that originated from the plant metabolism concept, a simplified version of industrial metabolism. It is based on Energy Material Flow Analysis (EMFA) and Life Cycle Assessment (LCA) tools for production plants' economic and sustainability assessment, using the I4.0 enabling technologies. A Multi-Criteria Decision Making (MCDM) method combines the two sustainability pillars for aiding companies in optimizing their production processes towards a reduction of energy/material flows. The combination of EMFA, LCA and MCDM tools into a plant metabolism-based model is the main novelty of this paper. The framework consists of three main phases. The first phase allows to model the manufacturing system by defining the plant layout, the assets, and the input/output flows. The second phase allows gathering information from the manufacturing plant to assess environmental and economic Key Performance Indicators (KPIs) following the LCA principles. The third phase consists of post-processing results, minimizing specific KPIs for establishing the optimal production scenario. A washing machine plant has been chosen as a case study to demonstrate the proposed method's capability in authentic contexts. Besides, the effectiveness in supporting companies in the analysis, identifying criticalities, and the proper energy and material flows management of production plants has been verified. Plant managers could use this framework for managing the production plans. From the scientific standpoint, the proposed method positively contributes to integrating the existing state of the art studies concerning the I4.0-related framework for the sustainability assessment and energy/material flows minimization of production systems.

Keywords: Energy/material flows | Industry 4.0 | Life cycle assessment | Manufacturing plant | Plant metabolism | Sustainable manufacturing

Abstract: Target design methodologies (DfX) were developed to cope with specific engineering design issues such as cost-effectiveness, manufacturability, assemblability, maintainability, among others. However, DfX methodologies are undergoing the lack of real integration with 3D CAD systems. Their principles are currently applied downstream of the 3D modelling by following the well-known rules available from the literature and engineers’ know-how (tacit internal knowledge). This paper provides a method to formalize complex DfX engineering knowledge into explicit knowledge that can be reused for Advanced Engineering Informatics to aid designers and engineers in developing mechanical products. This research work wants to define a general method (ontology) able to couple DfX design guidelines (engineering knowledge) with geometrical product features of a product 3D model (engineering parametric data). A common layer for all DfX methods (horizontal) and dedicated layers for each DfX method (vertical) allow creating the suitable ontology for the systematic collection of the DfX rules considering each target. Moreover, the proposed framework is the first step for developing (future work) a software tool to assist engineers and designers during product development (3D CAD modelling). A design for assembly (DfA) case study shows how to collect assembly rules in the given framework. It demonstrates the applicability of the CAD-integrated DfX system in the mechanical design of a jig-crane. Several benefits are recognized: (i) systematic collection of DfA rules for informatics development, (ii) identification of assembly issues in the product development process, and (iii) reduction of effort and time during the design review.

Keywords: CAD | Design guidelines | Design rules | DfX | Engineering knowledge | Feature recognition | Ontology

Abstract: Purpose To evaluate the accuracy of 3-D printed models of the femoral head based on preoperative computed tomography (CT) images. Other goals were to compare the cartilage thickness of bony specimen to the printed models and calculate the standard deviation between 3-D printed models based on CT images and laser scan models. Methods This retrospective study analyzed 10 patients who underwent preoperative CT imaging and hip replacement. Preoperative femoral head 3-D printed models were produced from CT images. Bony specimens were collected from surgical operations and scanned using CT and 3-D laser scanning, and cartilage thickness subsequently was measured by histological analysis. Comparisons of printed models based on CT images and printed models based on 3-D laser scanning were performed by overlapping their external surfaces using dedicated software and the standard deviation was calculated. Results The average standard deviation between the bony specimen 3-D models and preoperative 3-D printed CT femoral head models was 0.651 mm. The cartilage was approximately 1.487 mm thick. Discussion The comparison between preoperative CT image-based 3-D models and the postoperative bony specimenbased models permitted evaluation of the accuracy of preoperative CT image-based 3-D printed models. Cartilage thickness was estimated indirectly by comparing models obtained by CT and laser scanning, and it was related to the calculated standard deviation to overcome the cartilage detection limit of CT. This study shows how each step can generate accuracy errors on the final 3-D printed model. A repeatable and sustainable workflow for creating accurate and reproducible 3-D printed models could overcome this issue. Moreover, orthopedic surgeons should be aware of 3-D printed model precision in clinical practice. Conclusions This study provides encouraging results on the accuracy of 3-D printed models for surgical planning.

Keywords: 3-D printing | accuracy assessment | bone segmentation | femoral head model | hip replacement surgical procedure

Abstract: Since custom-made 3D printed surgical guides for maxillofacial surgery are usually expensive, Augmented Reality (AR) can be efficiently employed to overcome the high costs. The proposed work aims to develop and test an AR application for different maxillofacial surgeries. The application consists in overlaying the cutting lines on the patient’s mandible to guide the clinician during the procedure. It has been realized in Unity and preliminary tested with HoloLens 2 and a 3D printed mandible. Seven participants performed two consecutive trials. The mandible with the obtained surgical lines has been scanned after each test to digitally reconstruct the traced lines and compare them with the surgical lines previously designed. The results allowed the preliminary analysis of the developed AR system’s accuracy and precision. Mean distances from the designed surgical guides showed good accuracy for the genioplasty (deviation error around 1.03 mm) and orthognathic surgery (deviation error around 1.27 mm), suggesting the applicability of HoloLens 2 for these kinds of surgery. On the contrary, the application was not suitable for the mandibular angle osteotomy (deviation error over 2.50 mm).

Keywords: Augmented reality | HoloLens 2 | Maxillofacial surgery | Surgical guides

Abstract: The Selective Laser Melting (SLM) is accelerating the adoption of Additive Manufacturing (AM) technologies in the industry. One of the most critical benefits concerns the possibility of manufacturing complex-shaped components, which are not feasible or too expensive using traditional processes. Recent studies are evaluating the SLM manufacturability of closed impellers through laboratory tests. The adoption of numerical simulation models for achieving this goal is still limited due to the complexity of the additive process and the number of phases to be considered. The paper presents a numerical model developed in the ANSYS workbench platform for simulating the SLM process of closed impellers. This work is one of the first studies available in the literature for such a particular kind of components. The paper describes the overall simulation model and the steps required for its definition. Furthermore, boundary conditions and process parameters are provided for a better understanding of the model. A case study illustrates its application to a specific part, intending to evaluate (i) impact between the recoater and the component, (ii) maximum von Mises stress and (iii) maximum displacement during the printing phase and following post-processing. These evaluations will support design and manufacturing engineers during product and process engineering. The promising results of this study are encouraging further research about the application of SLM for closed impellers.

Keywords: Additive manufacturing | Impeller | Numerical simulation | Selective laser melting

Abstract: The Obstructive Sleep Apnea Syndrome (OSA) concerns episodes of complete or partial obstruction of the upper airway. Mandibular Advancement Device (MAD) is one of the most used systems for treating this syndrome. Clinicians frequently observe a combination of OSA and periodontitis. There is no research aiming to evaluate how periodontitis staging affects the overall mandibular and maxillary dental arches in the literature. Furthermore, no one has studied the combination between OSA and periodontitis and the effects of MADs on the patients in this condition. This paper aims to develop a numerical simulation approach based on FEM and evaluate the consequences (displacement and stress fields) of the periodontitis staging on PDL and teeth of patients suffering from OSA and treated with MADs. Simulations have been performed for evaluating Stage I of periodontitis. Results highlight a correlation between bone resorption and teeth displacement and periodontal ligaments stress (the higher the bone resorption, the higher the stress and displacement).

Keywords: Finite Element Analysis | Mandibular Advancement Device | Numerical simulation | Obstructive Sleep Apnea | Periodontitis

Abstract: Design for Manufacturing and Assembly (DfMA) is a consolidated engineering activity that suffers a real integration with 3D CAD systems. DfMA principles are currently applied downstream of the 3D modelling, by following the well-known rules available from the literature and company’s know-how. The paper provides a method to acquire, elaborate and represent DfMA rules sets to aid designers and engineers in developing mechanical products. This research work wants to define a general method able to couple DfMA design guidelines (knowledge-based design) with geometrical product features available by the investigation of the 3D model. The analysis of the 3D CAD model allows to anticipate manufacturing issues and to control manufacturing cost during product design. Moreover, a framework to embed this approach within a 3D CAD system is presented for future development in a software tool. Two case studies, a simple casing made of six parts and a centrifugal pump made of sixty-eight parts, highlight how the proposed method allows easy deployment of this approach in DfMA projects. Several benefits are recognized: (i) anticipation of manufacturing and assembly issues, (ii) reduction of manufacturing and assembly cost and, (iii) reduction of effort and time required by designers during the product development process.

Keywords: cad | design guidelines | dfa | DfM | feature recognition

Abstract: Several implant materials are used in cranial surgery. Still, each one has its drawbacks, such as the risk of infections, low mechanical strength, or low osseointegration. Implants with a porous surface are considered more effective than a smooth and rough coating. The porosity density and structure also influence the mechanical properties of the final implant. Moreover, the implant properties depend on the manufacturing method. This study aims to present a custom-made cranial scaffold composed of two distinct layers. A compact inner one guarantees adequate structural properties to the scaffold. In contrast, a porous outer one lightens the scaffold structure and assures the correct osseointegration. The customized scaffold has been designed through a 3D free-form modeling system. It can be manufactured by 3D printing techniques such as direct metal laser sintering in titanium or via selective laser sintering using PEEK. The advantages and limitations of the multi-layered custom-made scaffold and the related design process are qualitatively described.

Keywords: Additive manufacturing | Craniofacial reconstruction | Customized scaffolds | Multi-layered scaffolds | Porous scaffolds

Abstract: Fractures to the orbital walls and floor must be appropriately managed to avoid severe conditions. This results in particularly challenging anatomical reconstructions. The main issues are the implant’s proper shaping, placement, and orientation onto the eye socket. A new, customized implant-shaping mould has already been developed to shape patient-specific implants. However, it still does not address the implant positioning in the fractured orbital cavity. This present research aims to design, develop, and assess an innovative implant positioner to be used with the optimized version of the aforementioned implant-shaping mould. The new medical device was designed to be used with titanium meshes and deantigenated bone implants. It is easy to use, has a low cost, and is reusable several times. It is composed of (1) two coupled and hinged handles that allow the grasping of the implant, and (2) the positioner itself that permits proper implant placement and orientation. Selective laser sintering was used to print the mould and the new device in polyamide. Promising results for implant shaping, positioning, and orientation accuracy were obtained. An accuracy of 0.1 mm and 1.3 mm was, respectively, achieved for the implant shape and its placement in the mediolateral direction. The mean malrotation angle around the orbital rim was about 6°.

Abstract: Investment casting (IC) is a manufacturing process for making components giving an excellent surface finish, dimensional accuracy, and complex shapes. Despite these benefits, IC requires high cost and lead time for realizing the metallic mold for pattern manufacturing. To avoid the shortcoming of casting processes, Additive Manufacturing (AM) is widely used for fabricating patterns, cores, and molds (Rapid Casting - RC). Several applications concerning rapid investment casting (RIC) through Fused Filament Fabrication (FFF) and Stereolithography (SLA) were developed. However, a techno-economic analysis based on SLA application for RIC is missing. This paper presents a techno-economic analysis regarding SLA adoption for RIC. SLA is compared with wax injection, the traditional approach for realizing wax patterns. The article provides a decision-making tool that supports stakeholders in evaluating when AM is convenient (cost and lead time) for creating wax patterns, considering different production scenarios. For the compared technologies, the authors developed analytical cost models capable of assessing the cost of the entire production process and evaluating the post-processing phases. The following characteristics were considered: (i) different production volume, (ii) machine load factor, and (iii) parts features (i.e., dimensions and shape). The results show that SLA, for small parts, is more convenient than wax injection when the production volume is higher than 1E+03.

Keywords: 3D printing | additive manufacturing | cost estimation | investment casting | rapid casting | rapid tooling | stereolithography

Abstract: Engineering design shows a growing interest in exploring cost analysis to anticipate manufacturing issues and integrate production aspects within the product development process. This research aims to highlight key elements (inputs, parameters, models) to accurately predict the cost of a forged part using a complete model, with important information that can be available during the design phase. For this purpose, a systematic literature review of existing engineering methodologies developed for cost analysis of forged parts (i.e., cost estimation, DtC, and ABC) was performed with characterizations of the different approaches for evaluating the most important topics related to this objective. As a result, the most important insights related to the aim of this review are provided: (i) among quantitative methods, analytical and parametric models are the most suitable approaches to develop a cost estimation, (ii) a cost model based on a linear equation supported by single or multiple variables seems to be the most accurate tool to establish a robust cost analysis in the design of forged components, and (iii) input parameters related to the material type and geometrical features are the most critical cost-drivers in the cost assessment. Moreover, this review contributes to identifying emerging applications and obsolete topics, providing the ground to investigate unexplored areas relevant to future research.

Keywords: CAD | CAE | Cost assessment | Cost model | Engineering knowledge | Forging | Material processing | Systematic literature review

Abstract: Obstructive sleep apnoea (OSA) is a disorder characterised by complete or partial occlusion of the upper airway during sleep. Muscles relax during sleeping and collapse into the airway, closing the throat and prohibiting air flowing into the lungs. Different solutions have been adopted to manage the pathology to improve the life quality of affected patients. Mandibular advancement devices (MADs) are proven to be a compliant and successful therapy in the forward repositioning of the mandible to increase the upper airway volume. However, this method has some long-term adverse events that may affect the teeth and periodontal ligaments. This paper presents a finite element model to evaluate the MADs effects (displacement and stress) on teeth and periodontal ligaments, by varying the design, the point of application of the force and the material. The modelled bodies have been reconstructed through a Reverse Engineering approach and computer-aided design tools starting from tomographic images of anatomic bodies and from laser scans of a physical MAD. The results suggest that a central connection mechanism could affect mostly the anterior teeth. In contrast, a lateral connection mechanism provides a more uniform distribution of the load on teeth.

Keywords: Digital dentistry | Finite element method | Mandibular advancement device | Obstructive sleep apnea syndrome | Periodontal ligament

Abstract: Obstructive sleep apnoea syndrome is characterized by an obstruction in the upper airway due to the pharyngeal collapse during sleep. Mandibular advancement devices have gained success and large popularity as a non-invasive treatment for OSAS. Nevertheless, the effects of mandibular advancement devices were poorly investigated in literature. To this aim the paper proposes a procedure to achieve a numerical simulation model useful to assess the stress/strain distribution on the temporomandibular joint and periodontal ligaments caused by the mandibular advancement. The findings suggest that the mandibular roto-translation induced by the MAD provoke high stress on the molars and premolar teeth.

Keywords: Computer aided design | Finite element method | Mandibular advancement device | Periodontal ligaments | Temporomandibular joint

Abstract: Within the context of modern industries, additive manufacturing (AM) plays a critical role. Design for AM (DfAM) requires defining design actions related to the product's geometry under development. DfAM affects design choices such as the type of process, the material, the geometry, and the model's features. Knowledge-based engineering (KBE) is promising for integrating DfAM principles in the early phases of product development. Still, few limitations are noticed, such as the real interoperability between DfAM and 3D CAD systems, leading to the application of proper DfAM rules downstream of the 3D modeling. This paper aims to describe a method to formalize AM engineering knowledge used as a repository to develop a CAD-integrated decision support tool by acknowledging the current gap. The method uses, as input, geometrical data retrieved by the feature analysis of the 3D CAD model (feature recognition approach) and manufacturing information related to AM processes. The method will allow closing the gap between the design and production departments by creating a knowledge-based system. The outcome of this system does not concern the possibility of predicting the AM process parameters. The system will support engineers in delivering product designs compliant with AM processes. Based on this system, a CAD-integrated DfAM tool can be developed in the future.

Keywords: Additive manufacturing | Am | Cad | Design for additive manufacturing | Design rules | Design tool | Feature recognition | Knowledge-based system

Abstract: The ever-increasing competitiveness, due to the market globalisation, has forced the industries to modify their design and production strategies. Hence, it is crucial to estimate and optimise costs as early as possible since any following changes will negatively impact the redesign effort and lead time. This paper aims to compare different parametric cost estimation methods that can be used for analysing mechanical components. The current work presents a cost estimation methodology which uses non-historical data for the database population. The database is settled using should cost data obtained from analytical cost models implemented in a cost estimation software. Then, the paper compares different parametric cost modelling techniques (artificial neural networks, deep learning, random forest and linear regression) to define the best one for industrial components. Such methods have been tested on 9 axial compressor discs, different in dimensions. Then, by considering other materials and batch sizes, it was possible to reach a training dataset of 90 records. From the analysis carried out in this work, it is possible to conclude that the machine learning techniques are a valid alternative to the traditional linear regression ones.

Keywords: Conceptual design | Design costing | Early design phases | Machine learning

Abstract: The die manufacturing industry is widely based on the use of conventional machining tools. However, several studies have proposed Additive Manufacturing (AM) for molds and die inserts in the last ten years. The AM flexibility allows designing and manufacturing complex surfaces. This flexibility can be used to optimize the cooling channels of die inserts (conformal cooling). The research aims to evaluate whether Design for Additive Manufacturing commercial tools can be employed in redesigning die inserts. Besides, the paper describes a method to redesign a die insert for High-Pressure Die Casting using Selective Laser Melting. A test case is proposed to analyze an AM die insert's redesign process for improving the thermal exchange and the material distribution. The simulation of the AM process supports the drafting conclusions from the results.

Keywords: 3D Printing | Additive Design | Conformal Cooling | High Pressure Die Casting | Lattice Structure | Metal Additive Manufacturing | Rapid Tooling

Abstract: The paper proposes a method to couple manufacturing knowledge in the context of casting with 3D CAD modelling and design. The approach allows formalizing tacit into explicit design knowledge, for aiding engineers during the development of metal casted components. It is based on three main pillars: (i) identification of geometrical features (3D CAD features) and parameters that can cause an issue during the manufacturing process, (ii) definition of a numerical threshold for feature parameters that guarantee the feasibility of the casting process, and (iii) representation of design rules within a CAD system to support product design review. The method is considered the starting point for future developing a software tool (CAD tool plug-in), here just presented. Two case studies are reported with the aim to show the advantages of the proposed method and tool in the identification of manufacturing issues early in the product development process. Results highlight how the CAD-based tool is a useful assistant to avoid design problems related to the metal casting process.

Keywords: CAD | Design for casting | Design rules | DFMA | Embodiment design | Mechanical products

Abstract: The paper provides a method to acquire, process, and represent DfMA rules to help designers and engineers in the development of mechanical products compliant with manufacturing and assembly technology. This research work wants to define a general method able to link DfMA design guidelines (knowledge engineering) with geometrical product features that are available by the investigation of the 3D model. Numerical parameters of design features are related to design guidelines for the identification of manufacturing and assembly issues within the analysis of the 3D model.

Keywords: Design rules | DfMA | Embodiment design | Knowledge formalization | Mechanical products

Abstract: Obstructive sleep apnea syndrome (OSAS) is a sleep disorder that causes pauses in breathing or periods of shallow breathing during sleep. Mandibular advancement devices (MADs) represent a non-invasive treatment for OSAS that has had the highest development in recent years. Nevertheless, literature has not primarily investigated the effects of mandibular advancement. This paper presents a finite element method numerical simulation model for evaluating the stress/strain distribution on the temporomandibular joint (TMJ) and periodontal ligaments caused by advancement devices used for the treatment of OSAS. Results highlight that the mandible lift phase generates significant stress values on TMJ, which cannot be neglected for extended usage of MADs. Furthermore, mandible molar teeth are more loaded than incisor ones.

Keywords: Computer-Aided Design | Finite element method | Mandibular advancement device | Obstructive Sleep Apnea Syndrome | Virtual prototyping

Abstract: This paper presents a parametric cost model for estimating the raw material cost of components realized employing the investment casting process. The model is built using sensitivity analysis and regression methods on data generated by an analytic cost model previously developed and validated by the same authors. This is the first attempt of developing a parametric cost model for investment casting based on activity-based costing. The proposed cost model accounts component volume, material density and material price. The error in estimating the raw material cost for components whose volume is within the common range of investment casting is around 11%.

Keywords: Cost estimating relationship | Cost estimation | Investment casting | Parametric cost modelling | Sensitivity analysis

Abstract: Many companies have been evaluating the feasibility and gain of using Additive Manufacturing in their own business. One of the main advantages of this technology is the possibility to produce a shape with complex geometry in a reduced time. Therefore, Additive Manufacturing is often applied in rapid prototyping, which is an essential activity for the evaluation and testing of the design concepts. Even if the advantages and drawbacks of 3D printing are well known in the literature, there is still a lack of tools and methodologies to support a rapid techno-economic analysis for selecting the key manufacturing process between traditional machining tools and 3D printing. A case study on a 3D part of moderate complexity, a gas burner head, fabricated by additive manufacturing, using selective laser melting, has been described in this paper. This test case is focused on the context of rapid prototyping. The 3D part is a gas burner head which has to be printed for testing activity. The analysis focuses on the cost, time, and quality of the built part. An analytical approach has been proposed to calculate the cost of the 3D printing process. The analytical cost is related to the results of the numerical simulations to support the techno-economic analysis. The paper shows a method to compare additive manufacturing and traditional machining processes in rapid prototyping. However, the paper also shows a simulation activity to analyze with more details the 3D printing process in terms of part orientation and deformation of the build.

Keywords: 3D printing simulation | Additive manufacturing | Cost analysis | Metal printing | Rapid prototyping

Abstract: AIM: The purpose of this study is to compare the stress effects developed on the periodontal ligaments and teeth by three different types of mandibular advancement devices (MADs) using a finite element method (FEM) analysis. Introduction: Obstructive sleep apnea (OSA) is a disease with a high prevalence and, in recent years, the use of MADs as an alternative or support treatment to the continuous positive airway pressure (CPAP) has spread. Their use finds relative contraindications in the case of partial edentulism and severe periodontal disease. Given the widespread of periodontal problems, it is essential to know the effects that these devices cause on the periodontal ligament of the teeth. Materials and methods: Starting from the computed tomography (CT) scan of a patient’s skull, 3D reconstructions of the maxilla and mandible were implemented. Three different MADs were prepared for the patient, then 3D scanned, and lastly, coupled with the 3D models of the jaws. The devices have two different mechanics: One has a front reverse connecting rod (Orthoapnea™), and two have lateral propulsion (Somnodent™ and Herbst™). A FEM analysis was performed to calculate the stress applied on periodontal ligaments, on every single tooth and the displacement vectors that are generated by applying an advancement force on the mandible. Results: Herbst™ and Somnodent™ devices present very similar stress values, mainly concentrated on lateral teeth, but in general, the forces are very mild and distributed. The maximum stresses values are 3.27 kPa on periodontal ligaments and 287 kPa on teeth for Somnodent™ and 3.56 kPa on periodontal ligaments and 302 kPa on teeth for Herbst™. Orthoapnea™ has, instead, higher and concentrated stress values, especially in the anterior maxillary and mandibular area with 4.26 kPa and 600 kPa as maximum stress values, respectively, on periodontal ligaments and teeth. Conclusions: From the results, it is concluded that devices with a bilateral mechanism generate less and more distributed stress than an anterior connecting rod mechanism. Therefore, they may be advisable to patients with compromised periodontal conditions in the anterior area.

Keywords: Dental materials | Finite element method | Mandibular advancement device | Obstructive sleep apnea | Orthodontics

Abstract: Open-die forging is a manufacturing process commonly used for realising simple shaped components with high mechanical performances and limited capability in terms of production volume. To date, an analytical model for estimating the costs of components manufactured with this technology is still an open issue. The paper aims to define an analytical model for cost estimation of axisymmetric components manufactured by open-die forging technology. The model is grounded on the analysis of geometrical features available at the design stage providing a detailed cost breakdown in relation to all the process phases and the raw material. The model allows predicting product cost, linking geometrical features and cost items, to carry out design-to-cost actions oriented to the reduction of manufacturing cost. The model is mainly conceived for design engineers, cost engineers and buyers, respectively, for improving the product design, the manufacturing process and the supply chain. Cost model and related schemas for collecting equations and data are presented, including the approach for sizing the raw material and a set of rules for modelling the related cost. Finally, analytic equations for modelling the cost of the whole forging process (i.e. billet cutting, heating, pre-smoothing, smoothing, upsetting, max-shoulder cogging, necking and shoulders cogging) are reported. The cost model has been tested on eight cylindrical parts such as discs and shafts with different shapes, dimensions and materials. Two forge masters have been involved in the testing phase. The absolute average deviation between the actual and estimated costs is approximately 4% for raw material and 21% for the process. The absolute average deviation on the total cost (raw material and manufacturing process) is approximately 5%.

Keywords: Cost estimation | Cost model | Design features | Design-to-cost | Hot forging | Manufacturing parameters | Open-die forging

Abstract: This paper presents a methodological procedure, based on the anatomical reconstruction and constrained deformation, to design custom-made implants for forehead augmentation in people affected by Apert syndrome, experiencing a frontal bone deficiency. According to the anthropometric theory, a cranial landmarks identification procedure was applied to retrieve, from a repository, a healthy skull, used as reference geometry for implant modelling. Then, using constrained deformation and free-form modelling techniques, it was possible to design a patient-specific implant. At last, the implant was realised using a custom mould, specially designed according to the patient’s needs to provide an accurate fit of the defect site. The design procedure was tested on a patient suffering from Apert syndrome. Three implants were virtually modelled and 3D-printed for pre-surgical evaluation. Their shapes were 3D compared with a reference one (handcrafted by a surgeon) to test the accuracy. Deviations are negligible, and the customised implant fulfilled the surgeon’s requirements.

Keywords: Computer-aided design | Craniomaxillofacial surgery | Implant design | Medical devices | Rapid prototyping

Abstract: Background: Sleep-Related Breathing Disorders are characterized by repeated episodes of complete or partial obstruction of the upper airway during sleep. Mandibular advancement devices represent a non-invasive treatment in reducing the number of respiratory events and in decreasing symptoms. The advancement extent of these devices is responsible for the mandibular roto-translation and its effects on the temporomandibular joint. Methods: This study defined a systematic method to assess the mandible roto translation that is caused by MADs according to a scan-to-CAD approach. Starting from a closed mouth position and simulating the oral appliance at different settings it was possible to define a local reference system that is useful for the evaluation of the mandibular roto-translation. This latter was then applied to evaluate the movements of the condyle and the mandibular dental arch. Results: MAD1 resulted in a reduced mouth opening and protrusion, while MAD2 enabled a higher degree of motion of the mandible useful for patients who need an important protrusion. Conclusions: The two devices present different dynamics. Results that are achievable employing this method can be directly used by practitioners in comparing MADs, as well as by researchers in evaluating MADs effects.

Keywords: Computer-aided design | Digital dentistry | Digital workflow | Mandibular advancement device | Obstructive sleep apnea syndrome

Abstract: This paper proposes a methodological approach for the multi-objective optimization of steel towers made from prefabricated cylindrical stacks that are typically used in the oil and gas sector. The goal is to support engineers in designing economical products while meeting structural requirements. The multi-objective optimization approach involves the minimization of the weights and costs related to the manufacturing and assembly phases. The method is based on three optimization levels. The first is used in the preliminary design phase when a company receives a request for proposal. Here, minimal information on the order is available, and the time available to formulate an offer is limited. Thus, parametric cost models and simplified 1-D geometries are used in the optimization loop performed by genetic algorithms. The second phase, the embodiment design phase, starts when an offer becomes an order based on the results of the first stage. Simplified shell geometries and advanced parametric cost models are used in the optimization loop, which present a restricted problem domain. In the last phase involving detailed design, a full 3-D computer-aided design model is generated, and specific finite-element method simulations are performed. The cost estimations, given the high levels of detail considered, are analytic and are performed using dedicated software.

Keywords: Engineering-to-order (ETO) | Manufacturing cost estimation | Multi-objective optimization | Numerical simulation | Sequential optimization | Tubular steel towers

Abstract: This paper presents a novel framework for manufacturing and cost-related knowledge formalization. This artefact allows industries to capitalize the knowledge of experienced practitioners in the field of manufacturing and assembly, so that it can be used by designers for quickly and analytically estimating the production costs of components during product development. The framework consists of the following: (i) a cost breakdown structure used for splitting out the manufacturing cost, (ii) a data model (cost routing) to collect the knowledge required to define a manufacturing process, (iii) a data model (cost model) for collecting the knowledge required to compute the manufacturing cost of each operation within a manufacturing process, and (iv) a workflow to define the manufacturing process. The proposed framework provides several advantages: (i) knowledge formalization of product manufacturing cost, (ii) knowledge sharing among design/engineering departments, and (iii) knowledge capitalization for decision-making process. The proposed framework is used to formalize the knowledge required for analytically estimating the manufacturing cost of open-die forged components. Results highlight that the framework addresses the most important requirements for a knowledge-based cost estimation system.

Keywords: Computer-aided process planning | Design to cost | Knowledge elicitation | Manufacturing cost estimation | Manufacturing knowledge | Product design

Abstract: Analytical cost estimation of investment casted products during design phase is a complex task since the quantity of parameters to be evaluated. So far, there is a short literature on such cost estimation models. This paper attempts to improve the cost model presented by Boothroyd and Dewhurst. Improvements (mainly focused on cluster assembly and investment, sintering and melting phases) were defined and verified in cooperation with two foundries. Tested on eight components, deviation between estimated and actual costs is around 14% for manual production lines and 6% for automatic ones.

Keywords: cost estimation | design costing | design for x (DfX) | investment casting | process modelling

Abstract: The paper wants to improve the procurement processes for custom-made machineries and components. Indeed, the current methods and software platforms adopted by industries for purchasing machineries do not consider value generated through the entire lifecycle. Furthermore, the purchasing process of custom-made components from external suppliers is often and still characterized by several negotiation activities. This paper wants to improve this context by proposing two approaches to fostering the procurement processes. The first objective is to define an approach for standardizing the method for configuring machineries to be supplied from suppliers and to establish an approach for estimating their costs. The most important benefits of such an approach consist of (i) machinery selection based on the Total Value of Ownership (TVO), and (ii) optimized suppliers' selection by strengthening relationships between customers and suppliers. The second objective is to define a method and a software platform for managing the procurement phase of custom-made components. The most important benefits of this approach consist of (i) the standardization of procurement policies for custom and standard components, and (ii) the faster budgeting process. Future work consists of defining a reference model for gathering primary data required for TVO computation and defining standard agreements between suppliers and customers.

Keywords: Multi-criteria decision making | Suppliers selection | Total Cost of Ownership | Total Value of Ownership

Abstract: Design for disassembly is a key enabling strategy for the development of new business models based on the Industry 4.0 and circular economy paradigms. This paper attempts to define a method, based on Data Mining, for modelling disassembly data from large amount of records collected through the observation of de-manufacturing activities. The method allows to build a repository to characterize the disassembly time of joining elements (e.g. screws, nuts) considering different features and conditions. The approach was preliminary tested on a sample of 344 records for nuts disassembly retrieved by in-house tests. Disassembly time and corrective factors were assessed including the analysis of probability distribution function and standard deviation for each feature (i.e. disassembly tool).

Keywords: Big data analysis | Data mining | De-manufacturing | Design for disassembly | Disassembly time

Abstract: The transition toward smaller lot sizes in production requires the design of highly flexible processes where person and automation systems work together in a synergistic, safe and efficient manner. The new role of the operator requires researchers to study methods and tools able to evaluate the workers performance in order to maximize the comfort and quality of work. The virtual prototyping and simulation systems become fundamental to be able to design adequate production solutions, but before the tools it is necessary to study methods able to represent and consider the characteristics of the operators in the Industry 4.0-oriented factory environment appropriately. In this context, this paper proposes a method to assess the well-being of operators from different perspectives and, consequently, design operator-centered workstations. The first objective is preparatory in order to be able to fine-tune the second one, in a continuous improvement perspective. The approach has been successfully tested in collaboration with a food company.

Keywords: Ergonomics | Human-Centered Manufacturing | Operator 4.0

Abstract: The design of Engineer-To-Order products needs tools and methods for reducing time and cost during the phase of the quotation preparation. Modularization is one of the more applied design methods for ETO systems; however, it is necessary to integrate traditional tools with practices of design optimization to improve the development of a proposal. Even if commercial design tools for modeling specific types of engineering systems are available, the application of design optimization is still based on the use of tools not integrated with each level of the design phases. Moreover, these tools often require software customization. The integration of geometrical modeling, simulations, analysis, and optimization concerns the interaction between different tools. This paper describes an approach to support the Multi-Object Optimization related to the design of complex ETO systems with a focus on the oil & gas context. In this context, Genetic Algorithms and Constraint Satisfaction Problems are introduced as tools to support the design optimization of steel structures. The approach includes the employment of different and integrated tools throughout the design phases. This paper also shows a collection of tools to support the different levels for the design of different ETO products during the preparation of an offer related to proposal submission.

Keywords: Design optimization | Design tools and methods | Engineered-To-Order | Oil &amp; gas

Abstract: Target pricing is a methodology to develop competitive products by determining the target price from market analyses. To guarantee the right profit margin, target cost is a direct consequence of target price. In this situation, the manufacturing cost estimation at the design phase becomes an essential task. The paper presents a framework for collecting knowledge required for estimating manufacturing cost of components. The framework consists of: (i) a cost breakdown structure used for splitting manufacturing costs, (ii) a data model for collecting that knowledge required for defining manufacturing processes, (iii) a data model for the collecting that knowledge required for computing the manufacturing cost of each operation within a manufacturing process and (iv) a workflow for analytically estimating cost of components. The framework has been mainly conceived for managing components realized through forming and shaping processes. The result presented in this paper guarantee the following benefits: (i) knowledge elicitation on product manufacturing cost, (ii) knowledge sharing among design/engineering departments, and (iii) knowledge capitalization for decision-making process.

Keywords: Design for manufacturing | Design to Cost | Knowledge management | Manufacturing cost estimation

Abstract: Welding is a widely used technology that allows the joining of thick metal plates for the development of large structures (e.g. piping, tanks, vessels). Many industries are intensively using welding for manufacturing and assembly activities. Sustainability assessment of welded structures is currently performed with misleading information in terms of data heterogeneity (nature) and quality (source). The data required to carry out a robust environmental analysis are spread among different documents and become available only when the project is finalized. This paper aims to define a data framework for a life cycle inventory of metal arc welding processes to preventively assess the environmental performances of different processes for comparison and decision-making analysis. The framework is presented as innovative solutions for life cycle inventory that provide (i) a common data structure (model), (ii) necessary data (input/output), and (iii) physical allocation/placement of data (project design documents). This study was performed in accordance with the international standard organization ISO 14040/14044 by using an attributional life cycle assessment (aLCA). Two structures (an oil and gas riser and a ship hull) were investigated considering the same functional unit: the manufacturing, use, and disposal of a welded structure able to guarantee the engineering requirements (according to a specific standard) in terms of strain, stress, and corrosion allowance over the expected lifetime of 20 years. In both cases, the share of welding process in respect to an overall product/structure life cycle impact assessment is strictly dependant on the project design choice and can be negligible for high-corrosion-resistance materials (e.g., Inconel alloy). On the other hand, the use of traditional metals (e.g., carbon steel) allows a large decrease of the environmental load, and the influence of the welding process becomes significant in a life cycle perspective.

Keywords: Data framework | Design documents | Eco-design | LCA | LCI | Metal arc welding

Abstract: The eco-design of industrial products is a complex task that requires a high level of expertise in environmental science and a very large amount of data about the product under development. Product data for eco-design are not limited to geometrical and technical aspects; they also include information related to the product life cycle. The present paper aims to define a life cycle standard data model (LCSDM) that manages and shares life cycle information along the product development process. The LCSDM is defined as a common and structured framework for data collection in comparative evaluations. The need of a “standard” data model emerges in the context of life cycle assessment (LCA), mainly due to the subjectivity related to the life cycle inventory phase. The standard structure of the LCSDM facilitates the interoperability of eco-design software tools by creating a common framework for the implementation of eco-design initiatives inside product manufacturing companies. The LCSDM is a data structure that is able to represent the relationships among parts and assemblies. Each part or assembly is defined by a set of nodes that characterize the life cycle phases (e.g., Material, Manufacturing, Use, End-of-life, and Transport). A list of attributes is identified according to the environmental features that describe the product life cycle. The LCSDM structure is implemented in an encoding document for data sharing through a generic software language (e.g., XML – eXtensible Markup Language). The implementation of the proposed LCSDM in the design department of a manufacturing company using an eco-design software platform leads to the following benefits: (i) the fulfilment of the LCSDM (XML file) along the product development process, (ii) the use of a unique standard for data sharing among the several eco-design software tools, and (iii) the creation of a robust framework for life cycle assessment. The main drawback of the proposed LCSDM is related to the initial effort required to set up the design software platform (which consists of both standard and eco-design tools) to be able to read, fill, store and share the LCSDM.

Keywords: Data-exchange | Eco-design | Environmental analysis | Inter-operability | Life cycle inventory | Product life cycle

Abstract: Purpose: Orbital fractures are the most commonly encountered midfacial fractures, and usually, the fracture involves the floor and/or the medial wall of the orbit. This paper aims to present an innovative approach for primary and secondary reconstructions of fractured orbital walls through the use of computer-assisted techniques and additive manufacturing. Design/methodology/approach: First, through the 3D anatomical modelling, the geometry of the implant is shaped to fill the orbital defect and recover the facial symmetry. Subsequently, starting from the modelled implant, a customised mould is designed taking into account medical and technological requirements. Findings: The selective laser sintered mould is able to model and form several kind of prosthetic materials (e.g. titanium meshes and demineralised bone tissue), resulting in customised implants and allowing accurate orbital cavity reconstructions. The case study proved that this procedure, at the same time, reduces the morbidity on the patients, the duration of surgery and the related costs. Originality/value: This innovative approach has great potential, as it is an easy and in-office procedure, and it offers several advantages over other existing methods.

Keywords: Customized implant | Orbital cavity reconstruction | Reverse engineering | Selective laser sintering | Surgery | Surgical guide

Abstract: Design for end-of-life and design for disassembly are enabling design strategies for the implementation of business models based on the circular economy paradigm. The paper presents a method for calculating the effective disassembly sequence and time for industrial products. Five steps support designers in defining liaisons and related properties and precedence among components with the aim to calculate the best disassembly sequence and time. The effective disassembly time is computed considering the actual conditions of a product and its components (e.g. deformation, rust and wear) using corrective factors. This aspect represents the main contribution to the state of the art in the field of design for disassembly. The corrective factors are derived from a specific data mining process, based on the observation of real de-manufacturing activities. The proposed approach has been used for calculating the disassembly times of target components in a washing machine and in a coffee machine. The case studies highlight the method reliability of both: definition of time-effective disassembly sequences and assessment of effective disassembly times. In particular, a comparison of experimental tests shows a maximum deviation of −6% for the electric motor of the washing machine and −3% for the water pump of the coffee machine.

Keywords: data mining | de-manufacturing | design for disassembly | disassembly planning | estimated disassembly time | target disassembly

Abstract: The development of new and valuable products, from conceptual design to production, is to date supported by advanced methodologies based on ICT tools allowing many controls and checks before proceeding to heavy spending investment decisions. The increasing use ICT allow highlighting product design process and solutions able to improve people’s quality of life. Key product development principles based on human-centered approaches and eco-sustainability concepts prove to be themain factors affecting both the products’ users as well as the product manufacturing staff. This paper outlines product’s development approaches state of the art, foreseeing at the same time possible research trajectories to define manufacturing industry future scenario based on more sustainable economical, environmental and social design choices.

Abstract: This study defines a methodological procedure for the design and manufacturing of a prosthetic implant for the reconstruction of a midsagittal bony-deficiency of the skull due to the Apert congenital disorder. Conventional techniques for craniofacial defects reconstruction rely on the mirrored-image technique. When the cranial lesion extends over the midline or in case of bilateral defects, other approaches based on thin plate spline interpolation or constrained anatomical deformation are applied. The proposed method uses the anthropometric theory of cranial landmarks identification for the retrieval of a template healthy skull, useful as a guide in the successive implant design. Then, anatomical deformation of the region of interest and free-form modelling allow to get the customized shape of the implant. A full bulk and a porous implant have been provided according to the surgeon advises. The models have been 3D printed for a pre-surgical analysis and further treatment plan. They fulfilled the expectancies of the surgeon thus positive results are predictable. This methodology results to be reproducible to any other craniofacial defect spanning over the entire skull.

Keywords: Additive Manufacturing | Apert Syndrome | Biomedical design | Design process | Implant design

Abstract: Nowadays, design processes demand agile and flexible tools and methods to meet market needs. Virtual prototyping techniques are widespread in design strategies and practices, because these technologies reduce the project development lead-time and cost related to physical prototyping. The aim of this paper is the study and application of an approach for the modeling, simulation and geometrical optimization of fans for gas turbine air supply. Fan is a type of machine used to move a fluid, typically a gas such as air, exploiting the kinetic energy of a rotating impeller. It consists mainly of two components: housing and rotor. There is extensive literature on the design and optimization of industrial fan, but main works refer to a small or medium standardized fan, where it is possible to study many parameters and perform many experimental tests. The paper presents an approach for the efficiency optimization of large and customizable centrifugal industrial blowers for gas turbine air supply. The design variables investigated in this study were the blades quantity, orientation and shape. The proposed optimization method has been used for the design optimization of a blower for gas turbine power plant. The response surfaces allowed defining correlation between design variables and efficiency. The optimized design was 18 % more efficient than the original one.

Keywords: Computer aided engineering | Genetic algorithms | Geometric optimization | Industrial fan | Response surface methodology | Virtual prototyping

Abstract: Development of product architectures is a fundamental task in the conceptual design of complex products such as axial compressor of gas turbines. The definition of cost-effective architectures results from the introduction of conceptual cost estimation models aiming at the assessment of economical performances of different modules. Conceptual cost estimation means the product cost assessment in conceptual design phase. These models vary based on the technical and geometrical features of the defined product modules as well as to the specific manufacturing processes. The paper aims to describe the approach for early design cost estimation of Axial Compressor modules. The approach includes the design workflow and the required steps to build product architectures driven by cost indicator. The main limitation overtaken by the adoption of the proposed approach is the needs of a design tool able to characterize cost-effective design solution and to guide designer in product definition with the right level of confidence. The axial compressor product has been analyzed to retrieve different architectures and a case study of a rotor disc module is presented to demonstrate the feasibility of the proposed approach in the development of conceptual cost models starting from preliminary design information.

Keywords: Axial Compressor | Conceptual Costing | Conceptual Design | Product Architecture | Product Module

Abstract: One of the most important drivers for developing competitive products is cost. However, scientific and industrial communities are missing an effective cost management framework (including a solid method and a reliable tool) for supporting the product development process, from the initial design phases to procurement. For this reason, the paper presents a holistic ‘should costing’ methodology able to foster collaboration on cost-oriented solutions among company’s departments. The ‘should costing’ methodology and the related tool enable a systematic review of cost evolution, focusing on the opportunities to reduce costs, from the conceptual design stage through the overall production stages. In addition, the paper presents requirements for efficient implementation of a should-cost tool considering enterprise software solutions already available in manufacturing companies. A couple of companies (product manufacturers) adopted the recommended ‘should costing’ framework and quantitative and qualitative evaluations of the deployment process are presented as results. The benefits related with the adoption of the proposed should costing approach in relation with the traditional product development process is presented as well.

Keywords: Cost estimation | Design to cost | PDP | Product design | Product development process | Should costing | Suppliers selection

Abstract: Hot forging is an industrial process where a metal piece is formed through a series of dies which permanently change the shape of the part. Open-die forging is a particular type of hot forging in which the used dies are generally flat and the part to be formed has a simple shape. Manufacturing cost estimation is a well-debated topic, especially for traditional manufacturing technologies. However, only few models are available in scientific literature for the open-die forging process. This lack is due to the complexity of the process, characterized by a low level of automation and a high degree of expertise required to develop the process. The paper proposes an analytical model for the cost estimation of axisymmetric components realized using open die-forging. The model uses as input the geometrical features of the part (e.g. dimensions, shape, material and tolerances), and gives as output: (i) the time required for the process development, (ii) the amount of material needed for the part processing and, (iii) the forging machine size/type, from the cutting of the billet to the piece deformation. Two cylindrical discs have been analysed for validating the proposed cost estimation model. The case studies show that the cost models give an accurate result in terms of cost breakdown, allowing the designer a quick calculation of process costs.

Keywords: Analytical cost model | Cost estimation | Design features | Hot forging | Open-die forging

Abstract: Sheet metal forming of tribologically difficult materials (e.g. stainless steel) or forming in tribologically difficult conditions (e.g. ironing, punching, deep drawing) require the use of environmentally hazardous lubricants, such as chlorinated paraffin oils in order to avoid galling. The present paper describes an environmental and economic evaluation of two alternative sheet metal stamping processes. The forming of a sheet metal component for boiler burners has been taken as case study for the analyses. In particular, two different lubricants (standard mineral versus polymer matrix-based lubricant) have been tested and compared. However, the differences among the two processes involves not only the lubrication phase, but also the electric energy consumption during the stamping and degreasing, as well as the typology of solvent (perchloroethylene versus water). Results obtained with the economic analysis show that the use of the alternative lubricant leads to a 16% reduction of the total manufacturing cost, mainly due to the optimization of the degreasing. Concerning environmental results, instead, no relevant differences can be observed for almost all the considered impact categories (ReCiPe midpoint and endpoint), since the optimized phases are not the most critical ones.

Keywords: Cost estimation | Degreasing | Life cycle assessment | Lubricants | Sheet metal stamping

Abstract: The production cost is one of the most important drivers for product competitiveness. For increasing profits, a manufacturing process re-engineering is mandatory. This practice passes through systematic procedures for process selection, cost estimation and results analysis. This paper presents a method for evaluating different manufacturing alternatives for cost reduction. This method, composed of eight steps (most of them retrieved from the scientific literature), permits engineers to consider important aspects, such as the choice of cost estimation tools, the collection of data related to production processes, the impact related to the introduction of new production processes and the interpretation of results. Authors adopted such method for evaluating economic benefits of introducing a new manufacturing technology (i.e. investment casting) for three components of a food packaging machine. The adoption of the proposed method leads to compare investment casting vs. machining. The paper presents a detailed discussion of the economic benefits (return on investment, cash flows and manufacturing cost breakdown) related to the introduction of the investment casting technology.

Keywords: Concurrent engineering | Design for manufacturing | Design to cost | Investment casting | Product design

Abstract: Due to their high strength to weight ratio, composites materials have been historically used in high performance applications. Nowadays, they are no longer considered elitist materials due to the decrease of manufacturing costs reached thanks to innovative process processes such as Liquid Composite Molding (LCM) or pre-preg molding. The latter is suitable for structural parts, but its use is limited to simple geometry components without undercuts due to the rigid counter mold. Thus, a method called Air Press Molding (APM) has been developed. It exploits an inflatable counter mold to compact the laminate on the mold. This paper presents a Multi-Objective optimization approach for minimizing cost and temperature inhomogeneity of the heating system of the APM process. By using Genetic Algorithms and the Response Surface Methodology, the authors redesigned a 1250 [kg] aluminum mold, reaching a cost saving of 15 % and reducing the temperature variance of 77 %.

Keywords: Composite materials | Mold heating | Multi-Objective optimization | OOA processes

Abstract: The selection of cost-efficient supplying strategy is a process that involves different aspects, most of them linked with the design phase. Usually, this activity is performed at the procurement stage and does not engage designers and engineers who have drawn up the quality and cost characteristics of products. The paper presents a simplified analytic hierarchy process (AHP) for the concurrent evaluation of economic and quality factors of different supplying strategies. The goal of the AHP is to provide a tangible tool for designers and engineers for comparing supplying alternatives early in the design process. The hierarchy approach is used to organize objectives, criteria and alternatives according to priorities. A complex assembly of a machine tool has been analysed as a case study and four different suppliers with different features have been investigated using the AHP. Results highlight that, even if the lowest production cost can be obtained with Far East suppliers, considering quality criteria, national or local suppliers turn out to be the more appropriate and robust choice. The sensitivity analysis is beneficial to understand the level of confidence associated with the selection of one supplier in comparison with the other supplying strategies.

Keywords: Analytic Hierarchy Process | Manufacturing Strategy | Product Design | Supplier Selection | Vendor Rating

Abstract: Welding is considered an energy-intensive manufacturing system and it represents one of the most impacting construction process. The paper aims to define a structured data framework for life cycle inventory of a welding process starting from engineering and design documentation. The use of design documentation allows to perform robust LCA analysis which permits to compare the environmental performances of the most widely used welding technologies early in the design process. The necessary information to fill the data framework can be retrieved by available documentation developed in the preliminary design phase allowing to anticipate the life cycle analysis before the construction phase. A ship hull structure designed to be manufactured by the use of GMAW and GTAW welding processes has been analyzed as case study. The use of data framework facilitates the inventory phase creating a consistent and robust inventory for LCA.

Keywords: Data framework | Documentation | LCA | LCI | Welding technologies

Abstract: This paper defines a systematic workflow for production cost estimation of sheet metal stamped components. The approach represents a solution toward the adoption of Design to Cost methods during early product design. It consists in a sequence of steps that, starting from a 3D CAD model with annotations (material, roughness and tolerances) and production information (batch and production volume) leads to the manufacturing cost through an analytic cost breakdown (raw material, stamping and accessory processes, setup and tooling). The calculation process mainly consists in a first step where geometric algorithms calculate the sheet metal blank (dimensions, shape, thickness) and specific product features (e.g. flanges, louvers, embossing, etc.). The following steps allow to calculate the raw material, the stamping process and the process-related parameters, which are the manufacturing cost drivers (e.g. press, stamping rate/sequence/force and die dimensions/weight). The manufacturing cost is the sum of the previous calculated items. Testing the approach for three different components, the average absolute deviation measured between the estimated and actual cost was less than 10% and such a result looks promising for adopting this method for evaluating alternative design solutions.

Keywords: Cost estimation | Design to cost | Feature recognition | Sheet metal stamping

Abstract: The easy disassembly of certain product components is a prerequisite to guarantee an efficient recovery of parts and materials. This is one of the first step in the implementation of circular economy business models. Design for Disassembly (DfD) is a particular target design methodology supporting engineers in developing industrial products that can be easily disassembled into single components. The paper presents a method and a software tool for quantitatively assessing the disassemblability and recyclability of mechatronic products. The time-based method has been implemented in a software tool, called LeanDfD, which calculates the best disassembly sequences of target components considering disassembly precedencies, liaisons among components, and specific properties to model the real condition of the product at its End-of-Life (EoL). A dedicated repository has been developed to store and classify standard times and corrective factors of each disassembly liaison and operation. This knowledge feeds the two LeanDfD tool modules: (i) product disassemblability module, which allows to carry out the time-based analysis and to improve the disassemblability performance of target components, and (ii) product recyclability module, which estimates the quantities of materials that could be potentially recycled at the product EoL. The LeanDfD tool functionalities have been defined starting from the means of the user stories and the developed tool framework, data structure, databases and use scenarios are described. A group of designers/engineers used the tool during a re-design project of a washing machine, considering the disassemblability as the main driver. The case study highlights how the proposed DfD method and tool are able to support the implementation of re-design actions for improving product de-manufacturability and EoL performance. The LeanDfD features aid engineers in making a quick and robust assessment of their design choices by considering quantitative disassemblability and recyclability metrics.

Keywords: Design for disassembly tool | Disassembly sequence planning | Disassembly time | Recyclability

Abstract: Sustainability and cost optimization are actually the main drivers of product and system design in modern companies. However, cost assessments are usually carried out at the end of the design process to check the validity of the decisions already taken. Therefore, when targets are not achieved, numerous time-consuming iteration loops are necessary to optimize the initial solution. The paper situates in a research aimed at merging functional-based and design-to-cost approaches to propose a CAD-based platform able to assess new product variants from the earliest stages by configuring and assessing feasible design solutions. In particular, an approach is proposed for dealing with dependencies among design parameters in order to support the designer in a rapid definition of valid solutions and optimise them. The approach is described and then applied on an industrial test case, a bridge-crane design process.

Keywords: Design-to-cost | knowledge representation | object-oriented design

Abstract: OBJECTIVE The aim of this study is the evaluation of the temporomandibular joint stress distribution during the use of a Mandibular Advancement Device. MATERIALS AND METHODS This study is made using Finite Element Method (FEM). Dental casts, advancement bite, CBCT and MRI were taken in a 27-year-old woman. A Somnodent device was scanned and associated with a three-dimensional cranium. FEM analysis was made using ANSYS software with 1 and 2 mm of advancement. RESULTS The articular disc showed values range between 0.099-6.39 and 0.5-2.02 MPa for an advancement of 1 and 2 mm respectively. The condyle load distribution showed values range between 0.0037-7.50 and 0.0020-10.0 MPa for an advancement of 1 and 2 mm respectively. CONCLUSIONS Values obtained are significantly lower than limit values of the condyle and articular disc. Slight mandibular advancement can be consider a safe procedure even for the long period and should not cause permanent side effects.

Keywords: CBCT | Finite Element Method | Mandibular advancement device | OSAS | Temporomandibular joint

Abstract: The paper aims to evaluate the effects caused by a Mandibular Advancement Device (MAD) for Obstructive Sleep Apnoea Syndrome (OSAS) treatment. This study is based on Finite Element Method (FEM) for evaluating the load distribution on temporomandibular joint, especially on the mandibular condyle and disc, and on periodontal ligaments. The stress values on condyle and periodontal ligaments lead authors to consider MAD a safe procedure even for a long period. The obtained results also show the relationship between MAD material and load distribution at the periodontal ligaments. The paper is a step toward future analyses for studying and comparing the effects of MAD features, such as material, shape and dimensions, in order to allow the clinician prescribing the most fitting device.

Keywords: Finite element method | mandibular advancement device | obstruction sleep apnea syndrome | periodontal ligament | temporomandibular joint

Abstract: The cost reduction is one of the most spread strategy adopted by companies for guaranteeing profits in a competitive market. This paper presents an approach for the cost optimization of industrial electrical routings. The proposed optimization process consists of two levels: the arrangement of the cables within the cable trays and the 3D routing of the cable trays for connecting the modules of a product. The arrangement of the power and signal cables and the selection of the cable trays are carried out considering specific configuration rules. A genetic algorithm, coupled with the Hightower's algorithm, is used to solve the routing optimization problem. The proposed cost functions consider the raw materials and manufacturing/assembly operations. The optimization process has been used for optimizing a portion of the electric cable harness of a 43 MWe power plant with a size of 44 × 20 meters, and a total of 40,60 kilometers of cables. The optimization process let to a cost saving of about 15% compared to the design carried out with the traditional approach. Abbreviations:CTs: cable trays; CUi: hourly rate for the installation phase [€/hour]; CUrmtk: hourly rate for the k-th cost center used for transforming a semi-finished component [€/hour]; Cut: hourly rate for the test phase [€/hour]; CUtray: unitary cost of a cable tray [€]; DOE: design of experiment; GA: genetic algorithm [€]; Ic: installation cost [€]; If: installation factor [-]; PAc: cost for the preliminary analysis [€]; PAcp: percentage used for calculating the cost of the preliminary analysis [%]; RMc: cost of the raw material and relative transformation operations [€]; RMcci: cost of the i-th commercial component [€]; RMoc: percentage of the overhead costs related to the management of the raw material [%]; RMsc_scrapsj: cost of the scraps for the j-th semi-finished component [€]; RMscj: cost of the j-th semi-finished component [€]; RMtc: cost for transforming semi-finished components [€]; Tcl: commercial length of a straight cable tray [meter]; Tii,j: standard installation time for the i-th or j-th component [hour]; Tl: linear distance between two points of the wiring system that need to be connected [meter]; Trmtk: time for the k-th operation for transforming a semi-finished component [hour]; Ttk: standard test time for the k-th skid of the electrical system [hour].

Keywords: cable routing | Cost optimization | electric cable harness | oil &amp; gas

Abstract: The paper aims to explore the implementation of an eco-design methodology and the related software platform (G.EN.ESI–Green ENgineering dESIgn) within technical departments of a manufacturing firm. The G.EN.ESI eco-design methodology is based on the life cycle thinking concept and the software platform is conceived as a set of inter-operable software tools able to efficiently exchange data among them and with the traditional design systems (i.e. CAD, PDM and PLM). A multinational company, designing and producing household appliances, adopted the proposed methodology and related software platform for redesigning two cooker hood models with the aim to improve their environmental performances. Design and engineering departments evaluated the methodology and platform impact on the product development process, as well as the platform inter-operability with traditional design tools. The results indicate that methodology and software platform satisfy the requirements of the enterprise in terms of: (i) degree of expertise and training requirement on this subject, (ii) low impact in a consolidated design process and, (ii) good level of inter-operability among heterogeneous tools. However, the testing results highlight the necessity of a further platform optimisations in terms of software integration (single workbench made by integrated software tools with the same graphical user interface).

Keywords: BoM: Bill of Material | CAD: Computer-Aided Design | CAE: Computer-Assisted Engineering | CAS: Computer-Aided Software | CBR: Case Base Reasoning | CREER: Cluster Research, Excellence in Ecodesign &amp; Recycling | DB: Database | DfD: Design for Disassembly | DfEE: Design for Energy Efficiency | Eco-design methodology | eco-design software platform | EDIMS: EcoDesign Integration Method for SMEs | EoL: End of Life | EPD: Environmental Product Declaration | FMEA: Failure Mode and Effect Analysis | G.EN.ESI: Green ENgineering dESIgn | GUI: Graphic User Interface | interoperability evaluation | LCA: Life Cycle Assessment | LCC: Life Cycle Costing | LCT: Life Cycle Thinking | LE: Large Enterprises | LED: Light Emission Diode | PDM: Product Data Management | PDP: Product development Process | PLM: Product Life cycle Management | PMMA: Poly Methyl Methacrylate | product environmental sustainability | R&amp;D: Research and Development | REACH: Registration, Evaluation, Authorisation and Restriction of Chemicals | RoHS: Restriction of Hazardous Substances | SME: Small and Medium Enterprises | WEEE: Waste od Electric and Electronic Equipment | XML: Extensible Markup Language

Abstract: Conceptual design is a fundamental phase for developing optimal product configurations. During conceptual design, the degree of freedom in engineering choices can propose optimal solutions in terms of assembly, manufacturing, cost and material selection. Nevertheless, in current industrial practices, each aspect is analysed independently and a guided decision-making approach based on multi-objective criteria is missing. Multi-objective analysis is a way of combining each production aspect with the aim of choosing the best design option. The goal of this research work is to define a multi-objective design approach for the determination of optimal and feasible design options during the conceptual design phase. The approach is based on the concept of functional basis, module heuristics for defining product modules and the theory of multi-criteria decision-making for mathematical assessment of the best design option. The novelty of this approach lies in making the design process, currently based on company know-how and experience, systematic. A complex product (i.e. tool-holder carousel of a computer numerical control machine tool) is the case study used to assess the economic sustainability of different design options and to validate the proposed design workflow in a real manufacturing context. Different product modules have been re-designed and prototyped for comparing the assemblability, manufacturability and cost of the design solutions.

Keywords: Conceptual design | Design for manufacturing assembly | Design to cost | Multi-criteria decision making | Multi-objective design

Abstract: Circular economy (CE) is a new business model that is pressing manufacturing companies to think about closed loop scenarios for materials and products. Design for End-of-Life (DfEoL) and Design for Disassembly (DfD) are key enabling methods for the effective application of this model. The paper presents a time-based method for the calculation of disassembly sequences, adopting basic theories and techniques in this topic and integrating new concepts for the assessment of the disassembly time. The method consists of five steps and starts from the documentations (e.g., CAD model) generally available early in the product development process. The first three steps encompass the product analysis by including (i) the definition of target components from the general assembly, (ii) the analyses of the virtual model, and (iii) the assessment of the so-called level matrix, which is based on the concept of disassembly levels and liaisons characterization among components. The last two steps allow for the assessment of the time-based disassembly sequence by including (iv) the analysis of feasible sequences and (v) the generation of the best disassembly sequence for target components. The method mainly overcomes two issues highlighted in the literature regarding the reliability of the disassemblability analysis using a time-based approach and the quality of results accounting for the real condition of the product at the time of disassembly. The calculation of the effective disassembly time is grounded on a specific repository developed to gather knowledge about the disassembly tasks and related disassembly time. This is the main contribution and novelty of the proposed approach. By using the proposed method, different target components of a washing machine are analysed with the aim of demonstrating the robustness of the method and its consistency in the estimation of disassembly time. A maximum deviation of 10% between the estimated and measured disassembly times is noticed.

Keywords: De-manufacturing | Design for disassembly | Disassembly sequence planning | Disassembly time calculation | Level matrix | Target disassembly

Abstract: One of the most important driver for the development of competitive products is the cost. Despite most of the companies are focusing at the procurement stage (strategic sourcing) to reduce the cost of a product, around 80% of the final cost is determined at the design stage. Several software tools are currently available for Design to Cost. On the other side, “should cost” software tools allow to support the procurement phase. However, scienitific and industrial communities are missing an holistic “should costing” framework (method and tool) that accompany the product development process from design until procurement. To overcome this limitation, the paper presents a holistic “should costing” approach that integrates “should cost” and Design to Cost methodologies, covering design, engineering and procurement stages. Since dedicated software tools for “should costing” are required for the right implementation of this methodology, the paper describes stakeholders’ requirements for a benchmarking of such tools. The proposed “should costing” frameworjk has been adopted by a couple of companies (product manufacturers), describing their background, deployment process and achieved results. The manuscript ends with a list of the most important benefits of this approach.

Keywords: Design to Cost | Procurement | Should Costing | Suppliers selection

Abstract: This paper presents a knowledge-based method and relative multi-user web platform to prescribe Custom Made Insoles (CMI) involving the various stakeholders (patients/customers, practitioners, manufacturers and controllers) in an integrated approach that covers the entire process. The CMI prescription and design are carried out by using configuration rules, which combine foot parameters with insoles features. The platform also offers functionalities to collect and monitor the patients feedbacks, to control the clinician work and to obtain an electronic insole order used by manufactures.

Keywords: Co-design | Custom-made insole | Design knowledge | Healthcare design | Knowledge-based process

Abstract: Maritime vessels are complex products with long service life and great costs of building, manning, operating, maintaining and repairing. The paper aims to introduce a specific life cycle model and related metrics in shipbuilding design, supporting decision-making processes of material selection, manufacturing/assembly practices, maintenance, use, etc. The model provides a common structure for life cycle assessment (LCA) and life cycle cost analysis (LCCA) including the way to retrieve and to collect necessary data for the analysis starting from the available project documentation and design models. Different design configurations (materials, welding methods, etc.) for hull and hatches of a luxury yacht have been analysed using the proposed model.

Keywords: design | LCA | LCCA | maritime vessels | shipbuilding

Abstract: Promoting a more sustainable and energy-saving economy is one of the main goal of the European Community. In this context, home appliance manufacturers are researching and developing more efficient and sustainable products. Home automation and smart objects, by implementing specific energy management strategies, can significantly reduce energy waste. This paper aims to investigate the benefits offered, in terms of environmental impacts, by a smart system for kitchen air treatment. The system is composed by two inter-connected smart devices: a kitchen hood and an additional aspiration system able to assure a constant indoor comfort minimizing energy consumption and heat losses. Three different configurations were analyzed and compared: conventional extractor kitchen hood, smart extractor kitchen hood, and smart filtrating kitchen hood with smart additional aspiration system. Results show that in comparison with a traditional hood, products equipped with smart devices present lower environmental impact, due to the optimization of their energy consumptions.

Keywords: air quality assessment | household appliance | kitchen hood | life cycle assessment | smart objects

Abstract: Many foot pathologies are prevented or treated with Custom Made Insoles (CMIs). Although a strong computerization has characterized the shoe development process during the last decade, the CMI sector still lacks a software platform integrating the design and diagnosis tools used by the stakeholders of this area. Moreover, the prescription of CMIs is only based on the experience of skilled podiatrists rather than on a common and shared knowledge (e.g. guidelines, best practices, rules, etc.). This paper presents a multi-users and knowledge-based platform, called Smart Prescription Platform (SPP), covering the whole CMI development phases, from foot diagnosis to the production, involving clinicians, patients, manufacturers and controllers. The web-based platform is fully integrated with the technologies available in the orthopaedic sector, which are 3D/4D scanners, baropodometric platforms, footwear virtual catalogues, plantar pressure simulators, Augmented Reality devices and 3D CAD systems. The use of standard file formats (e.g.stl,.bmp,.xml) allows an electronic dataflow among the tools. The main module of the platform, called Prescription System (PS), is used for prescribing custom-made insoles for patients with different health conditions, satisfying the needs of all actors and optimizing the data exchange. PS is a knowledge-based prescription system integrating the best practices related to the prescription of CMIs. The PS output is a XML file representing the electronic order, used to exchange data with the other tools of the SPP. The proposed platform has been tested with a twofold aim: to validate the usability of the Prescription System and the inter-operability of the platform tools. The positive results gathered during the validation, led the experts to start using the web platform for their daily work.

Keywords: Collaborative platform | Custom Made Insole | Insole prescription | Knowledge-based platform | Web-based platform

Abstract: This paper presents an approach for the product multi-objective optimization by associating the Response Surface Methodology (RSM) and the Design of Experiments (DoE) technique with the CAD/CAE/DfC integration. The goal of this study is to empirically identify the relationships existing between the design features and the product response (stress, strain, cost, etc.). This approach integrates three different levels of analysis: optimization problem definition, virtual prototyping and design optimization. The optimization problem definition concerns in choosing the design variables, setting constrains that have to be observed and goals that have to be achieved. The virtual analysis allows defining the principal parameterization of a geometric model and simulating the performance of each configuration, at a specific working condition, while evaluating the manufacturing cost and time. The proposed approach investigates the effect of the defined parameters and noise factor on the experimental results. In particular, the applied method is based on virtual experiments according to the necessity to reduce time and costs in the early design phase. The loop of design-analysis-redesign during the optimization process is done automatically, without any interaction with the designer, by using a dedicated software tool. A test case is presented to show the characteristics of the methodology and to demonstrate its feasibility. Results demonstrate that the proposed approach significantly expedites the optimization process and reduces the computing cost compared to traditional approaches.

Keywords: CAD parameterization | Design for cost | multi-objective optimization

Abstract: Recently, environmentally conscious design and extended producer responsibility have become key aspects for companies that need to develop products that are sustainable along their whole life cycle. Design for End of Life (EoL) is a strategy that aims to reduce landfill waste through the implementation of closed-loop product life cycles. It is important to consider disassembly and EoL scenario management as early as the design phase. For these reasons, this paper presents an approach to help designers in the evaluation and subsequent improvement in product EoL performance. The method is based on four innovative EoL indices that compare different EoL scenarios for each product component. In this way, the designer can modify the product structure or the liaisons to maximise the reuse and remanufacture of components as well as material recycling. The presented case studies confirm the validity of the approach in helping designers during the redesign phase of goods and products to reduce the quantity of materials and industrial wastes sent to landfill.

Keywords: closed-loop scenarios | Design for EoL | EoL indices | EoL management

Abstract: Sustainability is becoming one of the main drivers of the modern product and system design. However, sustainability assessments are usually carried out at the end of the design process to check the validity of the decisions already taken. As a consequence, when targets are not achieved, numerous time-consuming iteration loops are necessary to optimize the initial solution. The paper merges functional-based and design-to-cost approaches to propose a CAD-based platform able to assess product lifecycle costs and impacts from the earliest design stages by configuring and assessing feasible design solutions. It considers both economic expenses and environmental impacts during all phases of product lifecycle on the basis of the company knowledge.

Keywords: CAD | Design-to-cost | functional design | lifecycle approach | sustainability

Abstract: Diagnosis and treatment of orbital wall fractures are based on both physical examination and computed tomography scan of the orbital cavity. The present paper reports on the secondary reconstruction of the skeletal orbit following untreated orbital floor fracture in a patient wearing an ocular prosthesis because of an orbital trauma. A computer-assisted approach, based on anatomical modelling and custom-made mould fabrication via selective laser sintering, is proposed for manufacturing a preformed orbital implant. Such a procedure offers precise and predictable results for orbital reconstructions. This protocol proved an effective reduction of operating time, patient morbidity and a fast and low-cost preoperative planning procedure. Such an approach can be used for immediate and in-office manufacturing of custom implants in trauma and reconstructive patients.

Keywords: computer aided surgery | ocular prosthesis | Orbital wall reconstruction | surgical tools

Abstract: This paper aims to analyze the attitude and the awareness of environmental sustainability issues within diverse Italian industrial companies. A survey has involved a balanced sample of companies operating in different industrial sectors. Considering the survey's results it can be concluded that: (i) environmental sustainability is an opportunity and a current market requirement, (ii) environmental sustainability is not formalized, since specific methods and tools are not used in technical departments, and (iii) environmental decisions are mainly made by specific key figures (i.e. energy/environmental manager). This analysis can be considered as a useful starting point for the framework formalization of eco-design approaches and tools able to bring eco-design principles into the work of technical departments with the aim to foster the future development of green and sustainable products and services.

Abstract: The paper proposes a methodological approach to support the multi-objective (i.e. cost and structural performance) optimization of complex systems, typical of the oil & gas sector. The complexity is managed through a double-level of optimization. The first one, based on simplified product models (1-D and 0-D), considers an analytical approach for the structural behavior and a parametric one for the cost estimation. The second level considers the use of a 3-D FEM solver for structural simulations, and an analytical tool for the cost estimation. As case study, the paper proposes the design optimization of an oil & gas chimney for gas turbines. The workflow analyzed during the case study describes the use of a multi-objective and multilevel approach to optimize cost, weigh, and structural behavior of oil & gas ducts.

Abstract: Cost estimation is a critical issue for many companies concerning both offers generation and company strategic evaluations. In this paper, a framework for early cost estimation has been proposed to some firms for an assessment of its main features. The aim of the industrial survey is to promote a discussion on the needs and the expectations regarding cost estimation in order to obtain feedbacks to be addresses in the implementation of a software tool. Gather data has led to a ranking of the main characteristics the tool should have.

Keywords: CAD | Design to Cost | Early cost estimation | Knowledge-based engineering | PLM | Product configuration

Abstract: In the current industrial context, where processes are extremely flexible to meet the changes of the market demand, the traditional strategies for managing the design and investment of industrial assets are too restrictive. Indeed, such strategies just consider the procurement price of an asset rather than its lifecycle cost. In this framework, the paper proposes a Total Cost of Ownership (TCO) model that can be adopted in B2B context for establishing the best asset configuration and procurement strategy by considering its CAPEX and OPEX. Such a TCO model has been implemented into an Enterprise Application Software for supporting the TCO evaluation. The presented model and software tool have been applied within an Italian food company for supporting the assets investment management.

Keywords: Asset management | Industrial plant configuration | Lifecycle approach | Suppliers selection | Total Cost of Ownership (TCO)

Abstract: The present paper aims at the definition of an analytical model for the cost estimation of the High Pressure Die Casting (HPDC) process. The model is based on two main pillars: (i) knowledge formalization and (ii) cost estimation algorithms. The novelty of this approach is the link between the analytical model (algorithms) and the geometrical features of the product under development. The relationship between geometrical features and cost items gives an accurate result in terms of cost breakdown, supporting designers for the application of Design-to-Cost rules in HPDC sector.

Keywords: analytical cost model | cost estimation | High Pressure Die Casting | knowledge formalization

Abstract: The Design to Cost method is a well-known methodology for developing cost-competitive products. In the context where the Industry 4.0 initiative is pushing the research on innovative systems for data exchange and analysis, the electric aspect of a product is becoming more and more important. The scientific and industrial literature contains several methods and tools for the cost estimation of electric cable harness, but they essentially calculate the cost by simply considering the Bill of Material and computing the cost of the raw material. The installation cost is not considered. The paper presents a Design to Cost method for electric cable harness, based on the analytic cost analysis of the raw material and routing process. The inputs of such a method are the electric Bill of Material and the 3D path of the cable harness. The cost consists of three items: purchasing, installation and cutting. The method, once implemented within a prototype software tool, has been applied for the cost optimization of the electric cable harness of an on-shore module for power generation. The average accuracy, measured comparing the results with experimental data, was 10.5%.

Keywords: Design costing | Design to X | Electric cable harness | Industrial design

Abstract: The custom-made insole is largely recognized as the most important orthotics for decreasing the foot plantar pressure, using additions or cutouts, which modify the geometry of the insole. This paper proposes a procedure for supporting the clinicians in prescribing innovative custom made insoles for offloading the plantar pressure by using specific combinations of materials for the foot peak-pressure areas, without modifying the geometry of the insole. The process starts with the acquisition of the plantar pressure map of the customer and ends with the definition of the customised insole. The aim of the procedure is choosing the best combination of materials for each foot anatomical area for reducing the plantar pressure peaks below a maximum admissible pressure value decided by the physician. The positions and dimensions of the inserts are defined through analyzing the customer plantar pressure while the inserts materials are defined using FEM simulations of the insole-foot interaction. The case study showed a plantar pressure reduction congruent with the FEM simulations results. This procedure is applicable both for subtractive and additive manufacture techniques.

Keywords: Biomedical design | Custom made insole | Design process | Pressure offloading | Simulation

Abstract: Electronics plays an essential role in many products and this leads to a larger production of e-wastes, currently recovered through impactful recycling processes. This paper proposes a web-based platform to implement reuse scenarios for electronic components. The objective is to create a structured portal where all the stakeholders can collaborate to extend the components lifespan and implement new circular business models. The final goal is to "close the gap" between the beginning and the end of life. The case study (industrial application) shows relevant benefits for the involved electronics manufacturer both in terms of environmental impact and economic savings.

Keywords: Collaborative platform | Decsion support system | Electronics reuse | EoL mangement

Abstract: The paper presents a lifecycle approach and the related software tool for the analysis and management of resource consumptions and environmental impacts of manufacturing plants. The approach, based on the industrial metabolism model, takes into account all the production and assembly aspects. The tool is able to assess the optimum working conditions for the minimization of resource consumptions (e.g. electricity) or environmental emissions (e.g. CO2). It provides a tangible support to guide decision-making strategies to move manufacturing towards sustainability. A manufacturing plant has been analysed for the model validation and the management of production scenarios, optimizing environmental and energy loads.

Keywords: Environmnetal impacts optimization | Plant lifecycle management | Resource consumption optimization | Software tool | Sustainable production

Abstract: Conceptual design is a central phase for the generation of the best product configurations. The design freedom suggests optimal solutions in terms of assembly, manufacturing, cost and material selection but a guided decision making approach based on multi-objective criteria is missing. The goal of this approach is to define a framework and a detailed approach for the definition of feasible design options and for the selection of the best one considering the combination of several production constrains and attributes. The approach is grounded on the concept of functional basis and the module heuristics used for the definition of product modules and the theory of Multi Criteria Decision Making approach (MCDM) for a mathematical assessment of the best design option. A complex product (tool-holder carousel of a machine tool) is used as a case study to validate the approach. Product modules have been re-designed and prototyped to efficiently assess the gain in terms of assembly time, manufacturability and costs.

Keywords: Conceptual design | Design for manufacturing and assembly | Design to cost | Making | Multi criteria decision | Multi-objective design

Abstract: Conceptual design is a central phase for the generation of the best product configurations. The design freedom suggests optimal solutions in terms of assembly, manufacturing, cost and material selection but a guided decision making approach based on multi-objective criteria is missing. The goal of this approach is to define a framework and a detailed approach for the definition of feasible design options and for the selection of the best one considering the combination of several production constrains and attributes. The approach is grounded on the concept of functional basis and the module heuristics used for the definition of product modules and the theory of Multi Criteria Decision Making approach (MCDM) for a mathematical assessment of the best design option. A complex product (tool-holder carousel of a machine tool) is used as a case study to validate the approach. Product modules have been re-designed and prototyped to efficiently assess the gain in terms of assembly time, manufacturability and costs.

Keywords: Conceptual design | Design for manufacturing and assembly | Design to cost | Multi criteria decision making | Multi-objective design

Abstract: Circular economy is largely recognized as the univocal economic model that guarantees a long-term sustainability, decoupling the economic growth and the finite resources consumption. As a prerequisite, it requires to realize product closed-loop lifecycles. However, the management of the EoL phase during the design process is a complex task, due to the fact that it is the most far away phase, in terms of time, from the moment of the product conception. For this reason, usually, manufacturers and EoL stakeholders do not actively collaborate in optimizing the product lifecycle performances. This paper wants to overcome this lack proposing a method to formalize, collect and classify the EoL knowledge. The main outcome is a structured database containing positive and negative knowledge about best practices and disassembly problems faced during dismantling activities. The knowledge classification rules are based both on product characteristics (e.g. product families, target components, assembly methods, etc.) and on other more general aspects (e.g. motivations of the disassembly, handling difficulties, etc.). Through the sharing of this knowledge, the gap between design departments and EoL stakeholders can be reduced with the aim to improve EoL performances and the overall resource efficiency. This work is focused on an out-of-service washing machine case study. The product has been manually disassembled by expert operators, observing and rating the significant problems. Their interpretation has allowed to create a set of specific design guidelines, organized according to the defined rules. The classified knowledge has been used by non-expert designers (undergraduate students) as a tool to guide the redesign activities. Different design solutions (e.g. homogenization of screws, reduction of component number, etc.) have been implemented to configure a new washing machine version, improved from the disassemblability point of view. The obtained results have confirmed the usefulness of the disassembly knowledge sharing in supporting Design for EoL activities and, furthermore, in non-skilled operators training. In conclusion, this research work contributes to the state of the art linking stakeholders involved in the Beginning of Life (BoL) with stakeholders responsible of the EoL management. Furthermore, the proposed work leads to relevant improvements in product lifecycle performances. The proposed knowledge database represents the needed resource to effectively extend the producer responsibility and to close the current gap between manufacturers and dismantlers.

Abstract: A growing interest toward sustainability actions at every level is characterizing the industrial sector. Following the environmental trend, further developments and improvements regarding the sustainability assessment of manufacturing processes is needed. With a particular focus on machining processes, the optimization of working parameters can represent a valid step forward in sustainable manufacturing. This paper aims to provide companies with the needed tool to independently asses the environmental performance of their customized machining operations. The purpose of the presented work is then to demonstrate that energy consumption calculated with empirical mathematical models available in literature, gives the greatest contribution to the environmental impact for a selection of machining processes by means of Life Cycle Assessment (LCA). Such objective lead to a clear need of specific models for the calculation of environmental impact of machining processes instead of available LCA datasets. Available mathematical models are adopted to provide a realistic energy consumption profile by using processing time variables. Such values are calculated through 3D models whose are used to recognize the needed manufacturing operations together with relative processing times. In order to validate the previous assumption, a couple of machining processes have been selected as reference and analyzed by setting up a detailed Life Cycle Inventory (LCI) model. Results shown that among the different inputs and outputs, the energy consumption carries the highest impact. Over 90% of the total impact for the chosen impact categories (Global Warming Potential and Eco-Costs) is attributable to the energy consumption meaning that, for the sake of simplification, the environmental profile of such operations is overlapped by its energy consumption.

Abstract: Conceptual design is a crucial activity in the product development process. The design freedom must consider a trade-off analysis among several aspects such as assembly, manufacturing, and costs. The goal of this approach is to define a multi-objective design approach for the determination of feasible design options. The approach is grounded on the concept of functional basis for the analysis of product modules and the theory of Multi Criteria Decision Making (MCDM) approach for the assessment of the best design option. A complex product (tool-holder carousel of a machine tool) is used as a case study to validate the approach.

Keywords: complex products | Conceptual design | design for assembly | multi-objective design

Abstract: Design-for-Assembly (DfA) and Conceptual DfA criteria are used in the generation of cost-effective assembly sequences for complex products. The design freedom suggests optimal solutions in the assembly time minimization problem regardless costs and issues about materials and manufacturing processes selection. The goal of this approach is to investigate how the application of the conceptual DfA affects the material and manufacturing costs (Design-to-Cost). A complex product (tool-holder carousel of a CNC machine) is used as a case study. The outcome is an approach to support designers and engineers in the re-design process for the product development and cost reduction.

Keywords: Conceptual Design for Assembly | Design to Cost | Manufacturability | tool-holder carousel

Abstract: Market competitiveness forces companies to explore novel methods and tools to make the overall product development (PD) agile and flexible and to reduce time to market. Accurate and fast cost estimation during design represents one of the most promising strategic actions to achieve these goals. In this context, a knowledge-based system that analyses the 3D CAD model of the product and automatically determines the manufacturing operations is developed. It consists of a scalable platform implementing "Design for Costing" paradigm. It is actually able to recognize geometric and non-geometric features from the 3D model and its attributes and calculate the final cost as the sum of raw materials, production cycles and setting operations thanks to the application of a set of knowledge-based rules mapping manufacturing processes and modeling features. While previous research works deepened the main technological issues of system development, this paper presents a practical case in ball valves industry to illustrate a structured methodology based on systematic engineering approach to apply the platform at the different stages of the product lifecycle and to verify the reliability of the implemented rules and the efficiency of the achieved process. The obtained results are compared to the traditional PD process to calculate product costs in order to highlight the main benefits.

Keywords: Cost Estimation | Design for Costing | Knowedge-based Rules | Modularity

Abstract: Nowadays, a large number of goods (e.g. appliances and electronic products) must be treated in dismantling centers after the conclusion of their lifecycle. Selective disassembly is necessary to accomplish environmental directives and to increase their sustainability. Dismantling centers developed internal non-standardized procedures to remove dangerous components and to minimize disassembly costs. The proposed approach aims to create a collection of the disassembly knowledge coming from dismantling centers as a repository for design actions oriented to End-of-Life. The final goal is to define a knowledge-based Design for Disassembly approach to support companies in designing products with improved disassemblability and maintainability.

Keywords: Design for disassembly | Disassembly Knowledge | Dismantling center

Abstract: The paper presents a lifecycle approach applied to the whole factory plant to characterize primary resource consumptions and environmental impacts for the different processes. The method is based on specific environmental models, defined for each process of a manufacturing plant. The goal is to provide a tangible support to guide decision-making strategies in order to move manufacturing towards sustainability. A case study of a washing machine factory plant has been analyzed to highlight the critical working areas in terms of environmental and energy loads and to support the identification of the corrective actions to increase the overall sustainability.

Keywords: Industrial metabolism | Life Cycle Assessment | Plant lifecycle

Abstract: The adoption of an eco-design approach is a key challenge for the total quality environmental management (TQEM). Recently, several eco-design methodologies have been presented, but none can be easily integrated in the traditional design process of manufacturing companies. The research presented in this paper aims to define a methodology, called G.EN.ESI, to help designers (especially those ones without a specific know-how on eco-design), during the development of sustainable products. In order to aid designers in the assessment of the environmental and cost impacts of a product, also a set of software tools have been defined. Using such a platform, the designer is supported by a robust workbench to perform all the analyses required to evaluate the product eco-sustainability for each phase of the product lifecycle. This software platform is essential for companies which want to implement the G.EN.ESI methodology without upsetting their own consolidated modus operandi and the internal organisation.

Keywords: Eco-design | Eco-design methodology | Environmental assessment tools | Environmental strategy | Integrated platform | Supply chain management | Sustainable design | Total quality environmental management | TQEM

Abstract: Patients affected by serious foot pathologies often require special orthotics to stand and walk correctly. Skilled operators obtain such insoles on the basis of manual procedures and following the prescriptions of orthopaedic technicians. The process is handicraft and time consuming. The paper presents a virtual prototyping approach which is based on dedicated foot scanners, CAD-based design tool and milling machines to obtain the bespoke footwear orthotics. The major contribution is a geometric procedure to design complex insole shapes starting from the foot scan and highly customized shoe lasts which are required in case of important deformities. The approach has been tested on several patients thanks to the collaboration with a partner insole producer and some orthopaedic centers. Patients have generally reported positive feedbacks on the comfort and functionality of the insoles.

Keywords: Foot orthotics | Insole design | Orthopaedic custom-made insoles

Abstract: According to the growing pressure on Sustainability issues from governances, manufacturing industries must pay their attention to optimize their processes. Anyway, it is necessary go behind this preliminary approach, extending the boundaries from the single company to the other actors that operate in the same supply chain. In this context, the paper proposes a methodology to increase the sustainability and to guarantee the traceability along the whole product supply chain. The methodology allows to model any supply chain, through the data collection from all the actors involved, and to measure the environmental sustainability, through the implementation of a distributed software system. The experimental case study, which involved a leather shoe supply chain, allowed to demonstrate the effectiveness of the approach in the selection of suppliers and in the optimization of the supply chain, taking into account the environmental aspects together with the other constraints such as design, costs and quality.

Keywords: Design for X (DfX) | Supply chain modelling | Sustainability | Traceability

Abstract: The Custom Made Insoles (CMI) context is characterized by a lot of software tools mainly used by skilled technicians of manufacturing companies. It is missing a tool to support the prescription of a CMI, mainly oriented to the podiatrists, but that could be used, at the same time, by customers, for self-monitoring activities, and by controllers to monitor the work of podiatrists. The paper aims to illustrate an innovative design process to prescribe a CMI, by using a knowledge-based web application: The prescription is based on configuration rules and templates, that provides to the clinicians a set of insole geometries and materials (knowledge-based approach). The proposed web platform Insole Designer is fully integrated with the most common monitoring devices (3D scanners and baropodometric platforms), 3D modelling software, and interactive shoes catalogues. The main output is the order (XML file) of the customised insole, used by an insole manufacturing company to produce the CMI. The validation is an ongoing activity, even if preliminary results are available. Italian podiatrists have been involved to evaluate each software module giving a score in a 3-point scale.

Keywords: Biomedical design | Custom Made Insole | Design process | Insole Design

Abstract: Due to the increasing pressure of legislations and market, the environmental sustainability is becoming a key competitive factor for companies. In specific markets, as the Northern Europe one, customers are very careful on the quality and sustainability of products, thus companies has to design and manufacture green goods. In this context, there is a strong need of effective design tools and platform which allows to configure products applying the life cycle paradigm and with the "environment on mind". Currently in the market there are only few examples of products designed taking into account the ecodesign concepts. In particular, for mechatronic or energy using products only the use phase is usually considered and all the re-design strategies aim to reduce the energy consumption. This is essentially due to the fact that there is a lack of tools and design platforms, which are easy to use and well integrated with the traditional design tools and with the design processes of companies. This paper wants to demonstrate the usefulness of a set of interoperable eco-design tools, the G.EN.ESI platform, in supporting the re-design of a mechatronic product. The proposed case study, realized in collaboration with an Italian leading company in the sector of household appliances, focuses on the improvement of a domestic cooker hood with the final objective to obtain a more sustainable product. The in-depth experimentation, for the duration of more than 3 months, involved different stakeholders within the company (designers, environmental expert, etc.), with the aim to validate the G.EN.ESI platform tools in different phases of the re-design process. The case study showed that the use of the platform has supported the company in the identification of the environmental hot-spots and during the product re-design phase, considering the whole life cycle. The re-engineered cooker hood exhibits relevant improvements in the most important environmental and economic indicators (environmental impact, energy efficiency, disassemblability, recyclability, etc.). Also a detailed analysis of the platform usability has been performed in order to measure if the tools completely fulfil the expectations of the final users. Finally, the level of integration within the company processes has been evaluated with a dedicated questionnaire. The results of these last analyses showed that the G.EN.ESI platform is appropriate to support a company to improve the sustainability of their products without the needs to heavily alter the traditional design process.

Abstract: The paper proposes a system to increase the environmental sustainability and to guarantee the traceability along the whole product supply chain. A methodology to efficiently model complex supply chains, share data between all the actors and measure the environmental sustainability, has been developed and implemented in a distributed software system. The experimental case study, realized in collaboration with a manufacturer of leather products, allowed demonstrating the effectiveness of the approach in the selection of suppliers and in the optimization of the whole supply chain, taking into account the environmental aspects together with the other constraints such as design, costs and quality.

Keywords: Life cycle assessment | Supply chain sustainability | Traceability

Abstract: The academic and industrial literature presents a lot of innovations to improve the energy efficiency of the home appliances around the world. However, few methodologies are able to combine innovations and eco-sustainability, during the design phase of green products. In this context, the paper defines an approach to analyse the relationships between different types of innovation and the relative environmental impacts, during the product lifecycle. The analysis has been performed by defining innovations categories and comparing the product Life Cycle Assessment before and after their implementation. This approach represents the preliminary phase of the innovation process, required to support the product manager. The approach has been experimented within a household appliances company, highlighting that there are innovations able to reduce the energy and water consumption respectively of 25% and 30%.©(2014) Trans Tech Publications, Switzerland.

Keywords: Household appliances | Life Cycle Assessment (LCA) | Product innovation

Abstract: Recently, the environmental problem has become a key issue for the modern society, due to the increase of pollution and global warming. Manufacturing industry is recognized as one of the main responsible of this situation, since it uses a large amount of energy and emits a relevant part of the total carbon dioxide. The only possible way to face this problem is the implementation of sustainable manufacturing approaches, in order to measure and reduce the global environmental impact of companies. In this context, the present paper focuses on a method for the pre-emptive evaluation of the environmental and economic sustainability of manufacturing lines/plants, considering the whole life cycle from line manufacturing and initial set-up, to the end of life (i.e. reuse/dismantling). A special attention has been paid in the use phase, since this one represents the most critical stage, as for all the energy using equipment. Its accurate modelling, considering each energy typology (electrical, thermal, etc.) with the relative detailed use scenarios (multiple working points for each equipment), is an essential prerequisite to estimate the global sustainability with an acceptable accuracy. The concurrent LCA and LCC analyses, realized on the basis of the production line life cycle model, considering the different cost items and environmental impacts, permits a company to estimate the overall sustainability of an existing or new line, understanding the most important criticalities, and evaluating possible alternatives through comparative analyses. A case study has been conducted thanks to the collaboration of a manufacturer of plastic extruded pipes. It demonstrated the usefulness of the proposed approach in the identification of the most critical line equipment/functional groups and in the evaluation of different scenarios for the line replacement, both from an environmental and economic point of view.

Keywords: Energy consumption | Environmental and economic sustainability | Sustainable manufacturing

Abstract: Nowadays, the environmental issue has become increasingly important and has taken a leading role in the product design process. The product sustainability pass through the use of specific software tools supporting the design phase. Their integration, to build up a platform, is a key aspect toward the implementation of an effective eco-design approach. Even if the approaches presented in literature to create an eco-design platform aim to integrate environmental aspects during the design process, a proper tools integration is not existing. To overcome these limitations, the paper presents an ecodesign platform in which tools for the improvement of the product environmental characteristics are contained. The tools of the platform are used to calculate the environmental impact of a product for each product life cycle phase: manufacturing, transportation, use and End of Life. The platform is completed by a tool containing the eco-design guidelines, also specific for the industrial sector of the company, used to suggest the designers how to improve the product eco-sustainability. The end users of the platform consist of designers from the design office but also from every department relevant for the project, mainly R&D, production, purchasing department, and quality. In particular, the following roles have been considered as users: designer, product manager, environmental manager and buyer. Designers and company experts use the same workspace, made of different tools. They can detail all the product life cycle phases, quantify the product performances, modify its.

Abstract: In order to favor the implementation of closed-loop scenarios at the product End of Life (EoL), it is essential to consider the disassembly phase during the design process. In this context, the paper presents a design for disassembly approach to quantitatively estimate the product disassemblability. The methodology is based on a knowledge database about liaisons, which have been classified and characterized with different properties, in order to take into account the liaison specificity and real conditions in the moment of the disassembly. Starting from the product structure and liaisons between components, the methodology allows to analytically calculate the disassembly time and cost of components/sub-assemblies. The case study (combination oven) demonstrates the usefulness of the proposed approach in identifying the product criticalities which is necessary to consider during the redesign phase in order to improve the product disassemblability performances.

Keywords: Corrective factors | Design for disassembly | Disassembly time and cost

Abstract: This paper presents a method to evaluate the environmental and economical sustainability of a manufacturing line/plant along its whole life cycle. The concurrent analysis of LCA and LCC allows the process engineers to estimate the production sustainability during the design of a new production line. The method considers costs and environmental impacts of the initial deployment (i.e. initial investment and set-up), use (i.e. workload or maintenance required by each machine) and end of life (i.e. retirement) of the analyzed system. The approach has been tested in a company that manufactures extruded pipes with the aim to evaluate the relative benefits. © 2014 Elsevier B.V.

Keywords: Energy consumption | Environmental and economical sustainability | Sustainable manufacturing

Abstract: Current CAD systems have dedicated functionalities to model weld beads, but it is often cumbersome to use these systems. This study presents a method to analyze the geometry of assemblies of B-Rep models to automatically identify possible welds among the parts using prediction rules. Adjacent faces are detected, and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The main goals of this study are to increase the speed of the welding definition process and to benefit applications such as the cost estimation of steelwork products. Cost estimates are based on the shape, the length and the dimension of each weld bead. Some industrial examples are presented to show the benefits in terms of time savings and accuracy to the estimation process. © 2013 © 2013 CAD Solutions, LLC.

Keywords: feature recognition | virtual prototyping of welds | weld beads identification

Abstract: The product eco-sustainability is recognized as a key factor for competitive products and recently lots of international directives (guidelines) have been issued. This paper aims to define a new methodology integrated in the product development process that, through the application of the most common eco-design guidelines and design past experiences, supports designers in the development of eco-sustainable products. Eco-design guidelines retrieved from the literature are subdivided according to a well-organized structure in "high level of abstraction" and "high level of detail" ones. In addition, Eco-knowledge is defined as all the choices and their related environmental performances, designers made during the design process of a product. The implementation of the proposed methodology in the product development process of an Italian cooker hood producer, allows to analyze the benefits achievable in terms of product eco-sustainability improvement. This analysis highlights that the proposed approach supports the implementation of eco-design principles, also in those companies without a specific background in eco-design.

Keywords: CBR | Decision making | Eco design | Eco-design guidelines | Sustainability

Abstract: Collaborative product design favours the identification of innovative solutions as well as enriching the experience of those who participate. Nevertheless, the design and supply chain integration in product development processes is not a trivial task. The main difficulties are related to the different levels of individual expertise amongst team members and to the different organisation of the companies involved. The complex scenario of the extended enterprise triggers research toward the development of efficient methods and tools to support the design teamwork. The present article illustrates an innovative co-design platform which implements an approach to support dynamic collaborative design processes. Starting from the definition of a new design process model integrating different collaborative dimensions, the proposed approach is based on the formalisation of the distributed knowledge in terms of interaction rules and representational models. In particular, the process variability is managed through a new dynamic workflow system able to handle unpredictable events occurring when multiple partners collaborate. Case Based Reasoning algorithms (CBR) are used to manage unexpected events. They support the identification of existing rules in order to reconfigure the workflow. Experimentation is carried out in order to identify the main advantages of the system and also critical issues. © 2013 Copyright Taylor and Francis Group, LLC.

Keywords: collaborative processes | concurrent engineering | dynamic environments | virtual enterprises

Abstract: Purpose During past years several eco-design methodologies have been previously defined but none can be easily integrated in the traditional design process of manufacturing companies. This paper wants to overcome this lack and aims to define a methodology, called G.EN.ESI, to help also those designers without a specific know-how on eco-design, during the development of sustainable products. Design/methodology/approach The proposed methodology is composed by six main steps defined to link the eco-design activities with the traditional design activities, to the aim of defining a TO-BE design process. Also new tools have been defined in order to help designers in the assessment of the environmental and cost impacts of a product. These tools have been integrated in an univocal software package, called G.EN.ESI platform. The platform is composed by four tools for the definition of the life cycle model of the product (one for each product life cycle phase), two tools for the assessment of the environmental and cost impacts and a tool to guide the decision-making process. Furthermore, a web module to retrieve the necessary data from the supply chain subjects has been defined. Finally, the link with the CAD and PLM systems is proposed to increase the usability of the platform. Originality/value Using such a platform, the designer is supported by a robust workbench to perform all the analyses required to evaluate the product eco-sustainability for each phase of the product lifecycle. Hence, this software package is essential for companies to implement all the methodology steps without the need to heavily alter the consolidated modus operandi and the internal organization.

Keywords: Eco-design methodology | G.EN.ESI platform | Sustainable design

Abstract: The product eco-sustainability is recognized as a key factor for competitive products and recently, lots of international directives (guidelines) have been issued. However, in literature does not exist research on the practical application of the guidelines during the design phase. The paper aims to define a new approach to support the product design, applying the most common eco-design guidelines integrated with the designers past experiences. This approach consists in a Case- Based Reasoning tool containing a repository of eco-design guidelines and knowledge relative to the past designers experience. The approach has been tested during the re-design process of a cooker hood.

Keywords: CBR | Eco-design guidelines | Eco-sustainability

Abstract: During past years several eco-design methodologies have been previously defined but none can be easily integrated in the traditional design process of manufacturing companies. This paper wants to overcome this lack and aims to define a methodology, called G.EN.ESI, to help also those designers without a specific know-how on eco-design, during the development of sustainable products. The methodology has been also contextualized in the traditional product design process, re-engineering this one with new input/output data, actors and specific tools, to demonstrate the applicability in real contexts. The re-engineered process is supported by a new set of integrated software tools, called G.EN.ESI platform. It is made of four tools for the definition of the product life cycle model, two tools for the evaluation of the environmental impact and Life Cycle Cost and a tool to guide the decision-making process during the re-design phase of a product. Furthermore, a web module to retrieve the necessary data from the supply chain subjects has been defined. Finally, the link with the CAD and PLM systems is proposed to increase the usability. Copyright © 2013 by ASME.

Abstract: Nowadays, industrial products, particularly household appliances, are strongly related to environmental issues. Due to high levels of uncertainty regarding design embodiments at the early design phase, new methods and tools are essential to provide designers a basis to determine the degree of sustainability of a given product. The paper aims to integrate ecodesign activities within the traditional flow of the product design process through the development of an integrated software platform which supports the decision-making task for product sustainability in the early phase of product design.

Keywords: Design for environment | Eco-design | Product development process

Abstract: In the context of a research program aiming at defining a framework to acquire patient data and support the whole shoe design and manufacturing process, this paper presents new CAD tools to design and validate lasts for shoes designed specifically for people with diabetes. Shoe last customising systems have already been proposed in the literature. However, tools for designing shoes for people with diabetes do not currently have the capacity to modify the last in order to reduce the risk of foot ulceration, whilst at the same time preserving the style of the shoe. The main contributions of the work are given by a method to identify the required design features to guarantee the footwear preventive function, the determination of a systematic protocol for orienting and measuring the virtual models of the feet and the lasts, and the definition of geometrical operators to modify the last shape according to its original aesthetic and the required footwear parameters. Such variables are computed by a knowledge based system on the basis of the patient's pathology. The paper presents the implementation of two CAD tools and describes the procedures and the geometrical algorithms to handle the last geometry. Finally a case study is reported to show the advantages provided by the proposed approach in terms of achieved quality of the design process and expected footwear performance. © 2013 Elsevier Ltd. All rights reserved.

Keywords: Diabetic foot | Foot-last fitting | Last design | Last measurement

Abstract: Welding is widely used in industry for products made of joined sheet metal parts and beams. The virtual prototyping process of welds in standard CAD systems relies on functionalities to manually add weld beads to the assembly models. Weld beads can be in the form of symbolic annotations or 3D solid representations. The size of products in terms of number of parts and required weld beads makes this process cumbersome and time consuming. This paper presents a method to analyze CAD models of product assemblies in order to automatically identify possible welds among the parts using geometric recognition rules. Adjacent faces are detected and Boolean operators on planar loops are used to identify bead paths. Beads are then split in homogeneous portions based on the topology of the connected parts. The geometrical analysis of the connected parts also allows a bead to be characterized in terms of thickness, type, length and accessibility. Finally, the user is provided with functionalities to edit manufacturing properties or exclude unwanted welds. The approach is applied at the design stage to rapidly come to the definition of the welds. If integrated with a CAD tool, this can be used as input for an efficient detailing phase. Moreover, the paper presents an application for the cost estimation of the designed welded product. Weld beads are given a realization time, and hence a cost, based on their geometric size and employed welding technology. Some examples from the industry are presented to show benefits in terms of time savings and accuracy of the cost estimation process. Copyright © 2012 by ASME.

Keywords: Cost estimation | Weald beads recognition

Abstract: In recent years, environmentally conscious design has become a fundamental approach for industries which have to consider the variable environment during the design process. Waste management is one of the most important aspects to be handled, to reduce the disposal in landfills and to encourage the sustainable 3R approach: Reuse, Recycling and Remanufacturing. Product disassembly is an essential phase of the product lifecycle, necessary to evaluate the End-of-Life (EoL) strategies and to reduce environmental impact. In order to minimize the impact on production and costs it is very important to consider EoL scenarios during the embodiment design phase, when designer's decisions influence product structure. Design for Disassembly (DFD) is a powerful method to reduce disassembly time and costs. However, there are no useful tools which provide guidelines to improve the product disassemblability or promote specific EoL scenarios. For these reasons this paper describes an innovative Design for Disassembly approach and related tool to support designers in product disassemblability evaluation. The tool has the scope to manage EoL scenarios for industrial waste in the early design phases and to share metadata with the traditional design tools. Disassembly costs is one of the most important parameters during the evaluation of EoL scenarios. Six indices are presented to evaluate the economic and environmental feasibility of the EoL strategies. The calculation of the six indices permits alternative EoL scenarios to be compared and encourage the recyclability, reusability or re-manufacturability of a product. These evaluations can be used to foster a particular EoL scenario, as early on as in the design process. The preliminary analysis on mechatronic products underline the utility of the software tool and indices. Product re-design, realized using this approach, shows a relevant decrease in environmental impacts and disassembly costs. As a consequence, the new product has a relevant percentage of components with a closed-loop lifecycle. © 2012 by ASME.

Abstract: Product disassembly is an important phase of the product lifecycle. It occurs to minimize the maintenance time and evaluate the End-of-Life (EoL) strategies, for example component reuse/recycling. These scenarios should be considered during the design process when decisions influence product architecture/structure. In this context, the present work describes an approach to support the designer's evaluation of disassemblability by using the 3D CAD model structure and suitable key indices related to product features. A software system allows the product model to be analyzed and evaluates the disassemblability degree. An experimental case study facilitates the approach demonstration and highlights product performance.

Keywords: Design for disassembly | End-of-Life | Industrial products

Abstract: Background: It is common practice to prescribe customised footwear to people with diabetes to reduce the risk of foot ulceration. Although shoe customising systems have been proposed, effective tools for designing shoe lasts for diabetic patients are lacking. The shape of the lasts must meet certain biomechanical objectives, while maintaining the style of the shoe.Method: The main contributions of this work are as follows: the creation of an artificial-neural-network-based framework to correlate foot measurements and medical data to required footwear features; the definition of repeatable geometrical procedures to measure foot and last scans; and the definition of geometrical operators to modify the last shape according to its original aesthetic and specific footwear parameters. These parameters are computed by a knowledge-based system on the basis of the patient's pathology and best practices of experienced technicians.Results: Dedicated software systems integrated in a common platform are implemented to support the last design process. Test case studies and a survey show the advantages provided by the proposed approach in terms of achieved quality and shoe developing time (72% time savings).Conclusions: A design framework with dedicated tools is proposed for the customisation of shoe lasts for diabetic patients. Further research should be focused on tools to design the insole, outsole and other shoe components. © 2012 Copyright Taylor and Francis Group, LLC.

Keywords: diabetic foot | foot-last fitting | last design | last measurement

Abstract: Machine design process requires the effective and rapid assessment of different design solutions. Beyond functions and technical performance other parameters as safety, manufacturability, assemblability etc. have to be taken into account. Manufacturing cost is one of the main factors in order to choose the most suitable solution, so accurate estimation in the early design phases is fundamental. Design to cost implies to manage a vast amount of manufacturing knowledge that has to be linked to the design parameters. Feature based 3D CAD models contain data useful for cost estimation but, despite the numerous researches on features recognition and extraction, no cost estimation software system yet assures reliable results. In such context, this paper presents an approach for rapid manufacturing cost estimation where design features are automatically linked to manufacturing operations. The approach has been implemented into a knowledge-based system and tested on practical case studies in order to validate the performance. Copyright © 2002-2012 The Design Society. All rights reserved.

Keywords: Design to cost | Feature-based costing | Knowledge-based system | Manufacturing features

Abstract: Diabetes is one of the main causes that generate foot health related diseases. It impacts on a large percentage of world population and is expected to grow in next 20 years. Good footwear is fundamental for influencing foot health status in particular when foot can be subjected to many serious problems as in case of diabetic patients. This research work faces this problem by defining an approach and related computeraided echnologies in order to properly design customized shoes for people suffering from diabetes. Design rules have been fixed by formalizing knowledge that expert podiatrists use to prevent foot diseases. Studied and implemented technologiesinterest the whole footwear design process: foot scanning, foot dynamic pressure measurement, design of last, insole and outsole. This paper is focused on the description of design software system structure and related tools, and, then, it reports preliminary experimental results on 20 case studies. © 2011 CAD Solutions, LLC.

Keywords: Cad modeling | Diabetes | Footwear customization

Abstract: Extended enterprises require novel modes of organizing companies and managing collaboration. Although the promise of Information Communication Technologies to connect people, processes and information, it is worth to notice that current implementations are strongly document-oriented and do not enable flexible workflow management overcoming well-known inter-enterprise integration difficulties. The long-term goal of the research is the study of a new methodology and the development of dedicated software tools to facilitate the dynamic collaboration among 21 companies participating to a research project, funded by the Italian Economic Ministry, called CO-ENV. The definition of dynamic workflow system architecture represents the step forwards the implementation of a collaborative platform. Preliminary benchmarking of available systems and techniques, the product development process analysis of the project participant companies and a possible structure of the system are well illustrated. Examples of expected and unexpected exceptions are reported and differences between static and dynamic workflow management systems are discussed. © 2010 Springer-Verlag.

Keywords: Design process | Dynamic workflow | Extended enterprise | Product innovation | Product lifecycle management

Abstract: Diabetes is one of the main causes that generate foot health related diseases. It impacts on a large percentage of world population and is expected to grow in next 20 years. Good footwear is fundamental for influencing foot health status in particular when foot can be subjected to many serious problems as in case of diabetic patients. This research work faces this problem by defining an approach and related computer-aided technologies in order to properly design customized shoes for people suffering from diabetes. Design rules have been fixed by formalizing knowledge that expert podiatrists use to prevent foot diseases. Studied and implemented technologies interest the whole footwear design process: foot scanning, foot dynamic pressure measurement, design of last, insole and outsole. This paper is focused on the description of design software system structure and related tools, and, then, it reports preliminary experimental results on 20 case studies. © 2011 CAD Solutions, LLC.

Keywords: CAD modeling | Diabetes | Footwear customization

Abstract: The increasing product complexity and the continuous need of improving product quality and services force companies to join into distributed and extended networks. Collaborative product development triggers research toward the development of new methods and tools to manage virtual teamwork to reduce time to market. In this context, the paper proposes a novel approach and a supporting co-design platform to manage interrelations across organisations. Experimentations into four product design chains show improvements in communication, information sharing, knowledge distribution, time saving and easiness of team management. They demonstrate that collaborative product development can be usefully enhanced only if tools and procedures are designed for the specific needs of the virtual network. Copyright © 2011 Inderscience Enterprises Ltd.

Keywords: Co-design platform | Collaborative product development | CPD | Distributed knowledge management | Virtual teamwork

Abstract: Collaborative design can provide creative design solutions and improve product quality as well as enrich the participants' knowledge. Nevertheless, design and supply chains integration in traditional product development processes is not a trivial task. The complex scenario of the extended enterprise triggers research toward the development of new methods and tools for managing virtual teamwork. The present research illustrates a novel approach to support multidisciplinary workgroups. It is based is based on the formalization of the distributed knowledge in terms of interaction rules and representational models. The result of the approach implementation is the definition of an innovative co-design platform supporting virtual teamwork during collaborative design activities. © Organizing Committee of TMCE 2010 Symposium.

Keywords: Co-design platform | Distributed knowledge management | Interaction patterns | Virtual teamwork

Abstract: 3D CAD systems are powerful tools for modelling rigid bodies but they are not adequate in order to model flexible material components, especially if a realistic simulation of physical behaviour is required as in virtual prototyping. This paper describes the methodology used to develop a knowledge-based system in order to automatically create virtual prototypes of uniaxial flexible components like cables, pipes and wires. The method has been translated in an operative design software system for metallic-reinforced elastomer hoses. The resulting VP tool integrates the 3D CAD technology and suitable structural simulation methods. The robustness of software system has been verified and errors are assessed. A dedicated experimental set-up has been realised in order to compare the virtual results with the real component behaviour. The system has been applied in the design of multifunctional agricultural machines showing reduction of physical prototypes and the lead-time due. © 2010 Inderscience Enterprises Ltd.

Keywords: fem simulation | flexible components design and modelling | knowledge-based design | virtual prototyping

Abstract: An efficient mechanical product design process implies the evaluation of many alternatives in a short time and rapid product changes on the basis of emerging needs. Product cost is one of the main factors in order to choose the most promising solution. Hence its accurate estimation in the design phases is fundamental. The main problem is the vast amount of knowledge that has to be managed in order to make robust evaluations. Features based 3D CAD models implicitly contain part of needed information. But such information has to be elaborated by adopting suitable rules based on manufacturing knowledge. In this context, the paper presents an approach and the related knowledge-based system able to automatically make reliable cost estimation starting from the 3D CAD model. The approach is based on the manufacturing knowledge formalization, on the geometrical and non-geometrical feature automatic recognition and, finally, on the mapping between manufacturing operations and modelling features. In order to validate the system performance case studies are reported. © 2010 Springer-Verlag London Limited.

Keywords: Cost estimation | Feature recognition | Knowledge-based systems

Abstract: Collaborative design provides creative design solutions and improves product quality as well as enriches participants' knowledge. Nevertheless, design and supply chain integration in product development processes is not a trivial task. The complex scenario of the dynamic extended enterprise triggers research toward the development of an innovative co-design platform to support multidisciplinary workgroups. Starting from the definition of a new design process model, the proposed approach is based on the formalization of the distributed knowledge in terms of interaction rules and representational models. © 2010 IFIP.

Keywords: agile organizations | collaborative design | virtual teamwork