Objective of the present work is the deep study of the manufacturing systems in terms of energy efficiency. Manufacturing enterprises have to reduce energy consumption for both cost saving and environmental friendliness, finding new ways to produce more with less. As a first step, clear definitions for the energy efficiency are provided, in order to successfully include this significant key performance indicator into the manufacturing decision-making attributes. These definitions are used in order to develop a generalized and holistic approach towards manufacturing energy efficiency. The basic element of the approach is the division of energy efficiency definition and study into four manufacturing levels, namely process, machine, production line, and factory. Process-level definitions are provided for the majority of manufacturing processes. A machine-level study indicates and solves difficulties, generated by the workpiece geometry, and points out the interaction with the process level through factors, such as the process time. Moreover, machine tool peripherals are responsible for a significant portion of the consumed energy. Classification of the machine peripherals, based on the dependence of their consumption on process variables, is required. Studies made on the production line and factory levels show that energy efficiency, at these levels, is heavily dependent on production planning and scheduling and can be improved through the appropriate utilization of machines, with the inclusion of shutdown and eco-modes. All the methods developed for each of the manufacturing levels are verified with appropriate case studies. Moreover, a holistic case study is presented, showing that many of the difficulties towards the optimization of energy efficiency can be dealt with successfully, using the proposed generalized approach. The implementation of the method in a software platform is presented. The tool is industrially evaluated using three case studies from three different industrial sectors (i.e. aeronautics, automotive and household). The evaluation of the presented case studies clearly reveals the usefulness and efficiency of the suggested approach validating its applicability to real industrial environments. This prototype information technology decision support tool can assist the manufacturing sector towards energy and eco-efficiency, within the context of a multi-objective optimization procedure, incorporating traditional metrics (i.e. time, cost, flexibility and quality), interacting with the machine monitoring systems. / Αντικείμενο της παρούσας διατριβής είναι η μελέτη της ενεργειακής αποδοτικότητας των συστημάτων παραγωγής. Η αύξηση της ενεργειακής αποδοτικότητας, προσφέρει μείωση του κόστους παραγωγής και των βλαβερών επιπτώσεων στο περιβάλλον. Αρχικά, παρέχονται ορισμοί για την ενεργειακή αποδοτικότητα, προκειμένου να συμπεριληφθεί και αυτός o σημαντικός δείκτης στα συνήθη κριτήρια λήψης αποφάσεων (δηλαδή το χρόνο, το κόστος, την ευελιξία και την ποιότητα). Οι ορισμοί αυτοί χρησιμοποιούνται για την ανάπτυξη μιας γενικευμένης και ολιστικής μεθοδολογίας ως προς την αύξηση της ενεργειακής αποδοτικότητας στα συστήματα παραγωγής. Το βασικό στοιχείο της μεθόδου είναι ο διαχωρισμός του ορισμού της ενεργειακής απόδοσης και της μελέτης του σε τέσσερα ιεραρχικά επίπεδα, ξεκινώντας από την διεργασία, τη εργαλειομηχανή, τη γραμμή παραγωγής και την μονάδα παραγωγής. Ορισμοί στο επίπεδο της διεργασίας, παρέχονται για την πλειονότητα των κατηγοριών των μηχανουργικών διεργασιών. Στο επίπεδο της εργαλειομηχανής μελετώνται οι διαφορές που προκύπτουν από την γεωμετρία του προϊόντος, και επισημαίνονται οι αλληλεπιδράσεις με το επίπεδο της διεργασίας μέσω παραγόντων, όπως ο χρόνος διεργασίας. Επιπλέον, αποδεικνύεται ότι τα περιφερειακά των εργαλειομηχανών είναι υπεύθυνα για ένα σημαντικό μέρος της καταναλισκόμενης ενέργειας. H ενεργειακή κατάταξη των περιφερειακών των εργαλειομηχανών, με βάση την εξάρτηση της κατανάλωσης τους από παραμέτρους της διεργασίας, είναι απαραίτητη. Μελέτες στα επίπεδο της γραμμής παραγωγής και της μονάδας παραγωγής, δείχνουν ότι η ενεργειακή αποδοτικότητα εξαρτάται σε μεγάλο βαθμό από τον χρονοπρογραμματισμό της παραγωγής και μπορεί να βελτιωθεί με την κατάλληλη αξιοποίηση των εργαλειομηχανών, συμπεριλαβαίνοντας τον τερματισμό της λειτουργιάς αυτών ή τη χρήση οικολογικών λειτουργιών (eco-modes). Όλες οι μέθοδοι που αναπτύχθηκαν για τα επίπεδα παραγωγής επαληθεύονται με μελέτες εφαρμογής. Για την υλοποίηση της μεθόδου αναπτύχθηκε λογισμικό το οποίο αξιολογήθηκε σε τρεις διαφορετικούς βιομηχανικούς τομείς με σημαντικά αποτελέσματα. Αυτό το πρωτότυπο εργαλείο υποστήριξης αποφάσεων μπορεί να βοηθήσει στην μείωση της ενεργειακής κατανάλωσης χρησιμοποιώντας πολύ-παραγοντική βελτιστοποίηση, λαμβάνοντας υπόψιν την ενεργειακή αποδοτικότητα μαζί με τα συνήθη κριτήρια λήψης αποφάσεων αλληλοεπιδρώντας με τα συστήματα παρακολούθησης των εργαλειομηχανών.

[ES] La Organización de las Naciones Unidas sugirió que entre los mayores desafíos de la humanidad se encontraba alcanzar un desarrollo sostenible en distintos aspectos medioambientales, económicos y sociales. De entre todos ellos, deberíamos considerar realizar aportaciones en los objetivos relacionados con los aspectos industriales y de producción. De esta forma, esta propuesta de investigación se inicia con la hipótesis de que es posible establecer una contribución referente a la fabricación sostenible que estructure el conocimiento y establezca directrices para una producción más limpia. La disertación comienza con una revisión de los trabajos previos en análisis de sostenibilidad aplicados a los sistemas de producción y a tecnologías de fabricación en general. El trabajo se centra, posteriormente, en el análisis sobre las tecnologías de arranque de viruta y las tendencias sobre sostenibilidad con la inquietud de encontrar los avances, las tendencias y los indicadores más utilizados. De esta forma, se identifica la oportunidad de implementar los criterios de sostenibilidad en los procesos de fabricación, para distintas etapas del ciclo de vida del producto y desde distintas perspectivas de análisis de materiales, producto y proceso. El resultado es una propuesta de modelo marco de procesos de conformado con flujos de materiales e información para definir los indicadores, durante las actividades del ciclo de vida del producto, alineados con los Objetivos de Desarrollo Sostenible. Como validación se ha elaborado una propuesta de conjunto de indicadores, para el caso de arranque de viruta, que contempla la triple dimensión de sostenibilidad, económica y social, las fases del ciclo de vida de producto y la perspectiva del tipo de análisis de ingeniería del proceso. La combinación de estos ha permitido definir una serie de matrices que contienen familias de indicadores que pueden desplegarse y adaptarse en función de la tecnología de conformado y proceso de fabricación. A nivel de detalle, la definición la familia de indicadores se establece en la fase de fabricación del producto en planta, donde se estructuran las métricas considerando la operación concreta de arranque de viruta y se determinan aquellos factores que influyen intrínsecamente. Por medio de una serie de experimentos se validó la toma de datos para cada indicador y se calcularon los indicadores agregados para facilitarlos en entornos colaborativos, potenciando la información estratégica, que puede ser analizada inmediatamente en cualquier plataforma digital colaborativa. Se define indicadores tecnológicos, como tiempos de mecanizado, estrategias de corte, integridad superficial, pero a la vez se evalúan aspectos como el clima social. En definitiva, podemos decir que sea se ha logrado realizar una aportación en el ámbito de la definición estructurada de indicadores para fabricación alineados con los colaborativos como parte de la definición de sistemas de indicadores equilibrados y alineados con objetivos de desarrollo sostenible. / [CAT] L'Organització de les Nacions Unides va suggerir que entre els majors desafiaments de la humanitat es trobava aconseguir un desenvolupament sostenible en diferents aspectes mediambientals, econòmics i socials. D'entre tots ells, hauríem de considerar realitzar aportacions en els objectius relacionats amb els aspectes industrials i de producció. D'aquesta manera, aquesta proposta d'investigació s'inicia amb la hipòtesi que és possible establir una contribució referent a la fabricació sostenible que estructure el coneixement i establisca directrius per a una producció més neta. La dissertació comença amb una revisió dels treballs previs en anàlisis de sostenibilitat aplicats als sistemes de producció i a tecnologies de fabricació en general. El treball se centra, posteriorment, en l'anàlisi sobre les tecnologies d'arrancada d'encenall i les tendències sobre sostenibilitat amb la inquietud de trobar els avanços, les tendències i els indicadors més utilitzats. D'aquesta manera, s'identifica l'oportunitat d'implementar els criteris de sostenibilitat en els processos de fabricació, per a diferents etapes del cicle de vida del producte i des de diferents perspectives d'anàlisis de materials, producte i procés. El resultat és una proposta de model marc de processos de conformat amb fluxos de materials i informació per a definir els indicadors, durant les activitats del cicle de vida del producte, alineats amb els Objectius de Desenvolupament Sostenible. Com a validació s'ha elaborat una proposta de conjunt d'indicadors, per al cas d'arrancada d'encenall, que contempla la triple dimensió de sostenibilitat, econòmica i social, les fases del cicle de vida de producte i la perspectiva del tipus d'anàlisi d'enginyeria del procés. La combinació d'aquests ha permés definir una sèrie de matrius que contenen famílies d'indicadors que poden desplegar-se i adaptar-se en funció de la tecnologia de conformat i procés de fabricació. A nivell de detall, la definició la família d'indicadors s'estableix en la fase de fabricació del producte en planta, on s'estructuren les mètriques considerant l'operació concreta d'arrancada d'encenall i es determinen aquells factors que influeixen intrínsecament. Per mitjà d'una sèrie d'experiments es va validar la presa de dades per a cada indicador i es van calcular els indicadors agregats per a facilitar-los en entorns col·laboratius, potenciant la informació estratègica, que pot ser analitzada immediatament en qualsevol plataforma digital col·laborativa. Es defineix indicadors tecnològics, com a temps de mecanitzat, estratègies de tall, integritat superficial, però alhora s'avaluen aspectes com el clima social. En definitiva, podem dir que siga s'ha aconseguit realitzar una aportació en l'àmbit de la definició estructurada d'indicadors per a fabricació alineats amb els col·laboratius com a part de la definició de sistemes d'indicadors equilibrats i alineats amb objectius de desenvolupament sostenible / [EN] The United Nations Organization suggested that among humanity's greatest challenges was to achieve sustainable development in different environmental, economic, and social aspects. Among all of them, we should consider making contributions to the objectives related to industrial and production aspects. In this way, this research proposal begins with the hypothesis that it is possible to establish a contribution regarding sustainable manufacturing that structures knowledge and establishes guidelines for cleaner production. The dissertation begins with a review of previous work in sustainability analysis applied to production systems and manufacturing technologies in general. Subsequently, the work focuses on the analysis of chip removal technologies and sustainability trends with the concern to find the most widely used advances, trends, and indicators. In this way, the opportunity to implement sustainability criteria in manufacturing processes is identified, for different stages of the product life cycle and from different perspectives of material, product, and process analysis. The result is a proposal for a framework model of manufacturing processes with material and information flows to define the indicators, during the activities of the product life cycle, aligned with the Sustainable Development Goals. As validation, a proposal for a set of indicators has been prepared, in the case of chip startup, which considers the triple dimension of sustainability, economic and social, the phases of the product life cycle and the perspective type of engineering analysis of the process. The combination of these has made it possible to define a series of matrices that contain families of indicators that can be deployed and adapted according to the forming technology and the manufacturing process. At the level of detail, the definition of the family of indicators is established in the manufacturing phase of the product in the plant, where the metrics are structured considering the specific chip removal operation and those factors that intrinsically influence are determined. Through a series of experiments, the data collection for each indicator was validated and the aggregated indicators were calculated to facilitate them in collaborative environments, enhancing strategic information, which can be immediately analyzed in any collaborative digital platform. Technological indicators are defined, such as machining times, cutting strategies, surface integrity, but at the same time aspects such as the social climate are evaluated. In short, we can say that it has been possible to contribute in the field of the structured definition of indicators for manufacturing aligned with collaborative ones as part of the definition of balanced indicator systems aligned with sustainable development objectives. / Ayabaca Sarria, CR. (2021). Desarrollo de un Modelo de Fabricación Sostenible aplicado a los Procesos de Arranque de Viruta en entornos colaborativos [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/174872 / TESIS

<p>One way to reduce the lifecycle cost and environmental impact of a product in a circular economy is to extend its lifespan by either creating longer-lasting products or managing the <a>product properly during its use stage. Life extension of a product is envisioned to help better utilize </a>raw materials efficiently and slow the rate of resource depletion. In the case of manufacturing equipment (e.g., an electric motor on a machine tool), securing reliable service life as well as the life extension are important for consistent production and operational excellence in a factory. However, manufacturing equipment is often utilized without a planned maintenance approach. Such a strategy frequently results in unplanned downtime, owing to unexpected failures. Scheduled maintenance replaces components frequently to avoid unexpected equipment stoppages, but increases the time associated with machine non-operation and maintenance cost. </p><p><br></p> <p>Recently, the emergence of Industry 4.0 and smart systems is leading to increasing attention to predictive maintenance (PdM) strategies that can decrease the cost of downtime and increase the availability (utilization rate) of manufacturing equipment. PdM also has the potential to foster sustainable practices in manufacturing by maximizing the useful lives of components. In addition, advances in sensor technology (e.g., lower fabrication cost) enable greater use of sensors in a factory, which in turn is producing greater and more diverse sets of data. Widespread use of wireless sensor networks (WSNs) and plug-and-play interfaces for the data collection on product/equipment states are allowing predictive maintenance on a much greater scale. Through advances in computing, big data analysis is faster/improved and has allowed maintenance to transition from run-to-failure to statistical inference-based or machine learning prediction methods.</p><p><br></p> <p>Moreover, maintenance practice in a factory is evolving from equipment “health management” to equipment “wellness” by establishing an integrated and collaborative manufacturing system that responds in real-time to changing conditions in a factory. The equipment wellness is an active process of becoming aware of the health condition and of making choices that achieve the full potential of the equipment. In order to enable this, a large amount of machine condition data obtained from sensors needs to be analyzed to diagnose the current health condition and predict future behavior (e.g., remaining useful life). If a fault is detected during this diagnosis, a root cause of a fault must be identified to extend equipment life and prevent problem reoccurrence.</p><p><br></p> <p>However, it is challenging to build a model capturing a relationship between multi-sensor signals and mechanical failures, considering the dynamic manufacturing environment and the complex mechanical system in equipment. Another key challenge is to obtain usable machine condition data to validate a method.</p><p><br></p> <p>A goal of the proposed work is to develop a systematic tool for maintenance in manufacturing plants using emerging technologies (e.g., AI, Smart Sensor, and IoT). The proposed method will facilitate decision-making that supports equipment maintenance by rapidly detecting a worn component and estimating remaining useful life. In order to diagnose and prognose a health condition of equipment, several data-driven models that describe the relationships between proxy measures (i.e., sensor signals) and machine health conditions are developed and validated through the experiment for several different manufacturing-oriented cases (e.g., cutting tool, gear, and bearing). To enhance the robustness and the prediction capability of the data-driven models, signal processing is conducted to preprocess the raw signals using domain knowledge. Through this process, useful features from the large dataset are extracted and selected, thus increasing computational efficiency in model training. To make a decision using the processed signals, a customized deep learning architecture for each case is designed to effectively and efficiently learn the relationship between the processed signals and the model’s outputs (e.g., health indicators). Ultimately, the method developed through this research helps to avoid catastrophic mechanical failures, products with unacceptable quality, defective products in the manufacturing process as well as to extend equipment service life.</p><p><br></p> <p>To summarize, in this dissertation, the assessment of technical, environmental and economic performance of the AI-driven method for the wellness of mechanical systems is conducted. The proposed methods are applied to (1) quantify the level of tool wear in a machining process, (2) detect different faults from a power transmission mini-motor testbed (CNN), (3) detect a fault in a motor operated under various rotation speeds, and (4) to predict the time to failure of rotating machinery. Also, the effectiveness of maintenance in the use stage is examined from an environmental and economic perspective using a power efficiency loss as a metric for decision making between repair and replacement.</p><br>

<p dir="ltr">This paper aims to gain a deep understanding of up-to-date research and development on modular self-reconfigurable robots (MSRs) through a thorough survey of market demands and published works on <i>design methodologies</i>, <i>system integration</i>, <i>advanced controls</i>, and <i>new applications</i>. Some limitations of existing mobile MSR are discussed from the reconfigurability perspective of mechanical structures, and a novel MSR system is proposed to address the identified limitations of existing MSRs. The comprehensive set of <i>Functional Requirements</i> (FRs) of MSRs is discussed, from which the mechanical designs of MSR were created, and the system was prototyped and built for testing. Three main innovations of the designed modules for MSR are to (1) share torque power, (2) customize the size for a given task, and (3) have a low number of actuated motors while still maintain a motion with high <i>Degrees of Freedom</i> (DoF) to overcome the constraints by the power capacities of individual motors; this helps to increase reconfigurability, reduce cost, and reduce the size of conventional MSRs.</p>

Sustainability has been the focus of intense discussions over the past two decades, with topics around the entire product life cycle. In the manufacturing phase, research has been focused solely on environmental impact assessment or environmental impact and cost analysis in its assessment of sustainability. However, few efforts have investigated sustainable production decision making, where engineers are required to concurrently consider economic, environmental, and social impacts. An approach is developed to assess broader sustainability impacts by conducting economic assessment, environmental impact assessment, and social impact assessment at the work cell level. The results from the assessments are then integrated into a sustainable manufacturing assessment framework, along with a modified weighting method based on pairwise comparison and an outranking decision making method. The approach is illustrated for a representative machining work cell producing stainless steel knives. Economic, environmental, and social impact results are compared for three production scenarios by applying the sustainable manufacturing assessment framework. Sensitivity analysis is conducted to study the robustness of the results. For future research, it is desired that a tool which integrates manufacturing information system information and the sustainable manufacturing assessment approach can be built to assist production engineers in considering sustainability performance when making decisions. / Graduation date: 2012

Introduction: Sustainability is humanity’s collective ability to sustain development that meets the needs of the present without compromising the ability of the future generations to meet their own needs. Preceding closely to the World Commission on Environment and Development (WCED) Report of 1987, the General Assembly has adopted the UN Declaration, in 1986 [GA RES. 41/128] and has re-emphasized its importance in the UN Millennium Declaration, 2000. Given this anthropocentric rights basis of sustainability it becomes necessary to understand what this ability and development are with respect to the individual human. Problems of relevance, whose resolution benefits more people in general, are often intractable to the methods of rigorous problem-solving (1). Systemic problems of development score high on relevance, low on being amenable to rigor (1) and are considered wicked in nature (2). Consequently, the concern for sustaining human development is wicked and hence calls for taking a design approach as design is considered good at resolving wicked problems(3). This suggests that the collective ability for sustainability with respect to the individual is design ability i.e. to specify solutions that satisfy requirements arising from having to meet self-determined individual (human) developmental needs. However, literature connecting design, sustainability and human development systemically is found lacking and calls for conducting integrative trans-disciplinary research. Prevention and remedial of consequences of technology to the habitability of earth requires the identification, understanding and control of interactions between humans and between humans and the earth systems. These interactions need to be identified generally and understood systemically in the context of being able to sustain human development. However, despite this need for research in interactions and an integrative framework for informing interventions (4) to prevent or remedy unsustainable situations literature that addresses this need is found inadequate. Research Objective: To develop a descriptive model of interaction to be able to identify and describe interactions and understand interactions at human-scale. To develop a prescriptive framework within which to situate the prevention and remedial of problems related to un sustainability by design and prescribe conditions that ensure coherence of design interventions to principles. Research Method: As is the nature of problems of relevance, the proposed research by nature spans multiple disciplines. Descriptive inquiry into widespread literature spanning conservation, development, systems theory and design is conducted before synthesizing a descriptive model of interaction that situates design cycle as a natural cycle based on interpretation of entropy and Gestalt theory of human perception. A manual discourse analysis of a section of the WCED report is undertaken to inquire into the conceptual system (worldview) behind sustainable development to understand human interactions based on worldview. Addressing the need for choosing alternative goals of development for sustainability, Sen’s capability approach to human development is adopted after critically reviewing literature in this area and synthesizing an appropriate integration of design ability, tools, (cognitive) extension and design capability for human development. Models based on theories spanning design expertise, psychology and systems thinking are reviewed and synthesized into a prescriptive framework and two intervention scenarios based on it. The framework, intervention scenarios and the model are illustrated with evidence from qualitative bibliographic analysis of several cases related to sustaining human development in principle. Results: Sustainability is proposed as a human ability; this human ability is proposed to be design ability to sustain human development. A descriptive model of interaction that situates anthropogenic action as a design cycle is proposed. Based on this model, identifying entities and interactions is demonstrated with examples. It is proposed that humans interact, designing, due to and based on their worldview. Expansion of capabilities as stated in capability approach to lead to human development is ‘extension’ of design ability to design capability mediated by tools. Personal and interpersonal interactions at human scale are described through tool-use categories. A prescriptive framework for sustainability by design that holds human needs as central to interventions for sustainability is proposed. Based on this framework, pro-active and reactive scenarios of design intervention for prevention and remedial of un sustainability are constructed and demonstrated using several cases. Summary: Problems of relevance like sustaining human development are wicked in nature and require knowledge and action mutually informing each other. Addressing the inter-disciplinary nature of the problem requires a design approach as design is known to integrate knowledge from several disciplines to resolve wicked problems. The imperative to be able to sustain human development provides the widest profile of requirements to be met and design is shown to be central to meeting these requirements at the various scales that they surface. Sustainability is defined as humanity’s collective ability to develop meeting needs of the present without compromising the ability of the future generations for meeting their own needs. This collective ability translates to the individual’s design ability to specify solutions that satisfy requirements arising out of having to meet self-determined developmental needs. The process of ‘expansion’ -- of capabilities that free people choose and value – that realizes human development is the process of tools affording the extension of design ability to design capability necessary for progressively satisfying requirements arising out of self-determined needs of increasing complexity. It is proposed that humans interact, designing based on and due to their worldview. Personal and interpersonal interactions at human scale are described through tool-use categories. A prescriptive framework for sustainability by design is developed stating conditions to guide systemic design interventions for preventing and remedying unsustainability within pro-active and reactive scenarios respectively. A descriptive model of interaction is developed to situate and enable understanding of interactions. The framework, scenarios and the model are illustrated using several cases related to sustaining human development.

Global consumption levels currently extend far beyond what planet Earth in terms of natural resources can regenerate in a sustainable manor and will by 2050 reach levels corresponding to what it would require three Earths to sustain. This overexploitation and unsustainable management of the Earth’s resources in combination with the necessity of mitigating climate change and reaching net zero CO2 emissions by 2050 require action across all sectors, not least the manufacturing industry. This thesis covers how large manufacturing enterprises can implement and utilize strategic targets and Key Performance Indicators (KPIs) to align with the principles of a Circular Economy (CE), and as a result, improve sustainability and business performance. Based on a case study conducted at Siemens Energy (SE) involving a literature study, interview study, and focus groups, a carefully selected set of strategic circularity targets and KPIs are presented to measure, evaluate, and drive circularity performance within large manufacturing enterprises. Since the thesis’ ambition was to provide valuable insights beyond SE, strategic circularity targets and KPIs specifically directed at SE were further generalized to be universally relevant for academia and other large manufacturing enterprises. Enterprises within the given sector share several key characteristics such as extensive material resource flows and complex value chains, hence strategic targets and KPIs emphasize material efficiency through decreasing virgin material dependency, increasing recirculation rates, and transitioning towards circular business models. While suggested targets and KPIs are universally directed at large manufacturing enterprises, individual organizations are recommended to conduct internal investigations and analyzes to further tailor and adapt strategic targets and KPIs towards the specific enterprise. In addition to strategic targets and KPIs, the thesis also presents an overview of opportunities, benefits, risks, and potential impacts for large manufacturing enterprises aspiring to increase circular initiatives, highlighting key principles to manage risk and capitalize on opportunities. The findings conclude that the main opportunity enabled by CE is to leverage synergies which align environmental, economic, and strategic corporate incentives, with key benefits including aspects such as decarbonization and reduced environmental impact, increased revenues and cost savings, risk management, and new business opportunities. Risks associated with CE include rebound effects, organizational insufficiencies, lack of material quality and safety, as well as a low product performance, which further can lead to potential impacts mitigating the positive effects of CE, or at worst setbacks causing a net negative output from implemented circular measures. In summary, the opportunities and benefits associated with CE are many, but implemented circular measures require risk awareness and continuous management to ensure efficiency.

<p dir="ltr">In our daily lives, we rely on a multitude of discrete products to meet our needs. Traditional product design approaches have primarily focused on economic and technical aspects, often overlooking the pressing environmental and social challenges facing society. Recognizing the limitations of our ecological systems to cope with the waste generated by our current industrial processes, there is a growing need to anticipate the potential consequences of product design across technical, economic, environmental, and social dimensions to pave the way for a sustainable future. One promising strategy within this context is the integration of sustainability principles into optimization-based design models that consider a product's entire life cycle. While there have been previous efforts to optimize product life cycles, a comprehensive exploration of optimization-based design methods with a focus on multiple objectives for discrete products is essential. This dissertation explores the integration of sustainability principles with optimization-based design by taking the electric traction motor used in electric vehicles as a case study. This complex and environmentally significant technology is ideal for investigating the tradeoffs and benefits of incorporating sustainability objectives into the design process.</p><p dir="ltr">The key tasks undertaken in this study are as follows:</p><ul><li>Development of a parametric design and optimization framework for a surface-mounted permanent magnet synchronous motor. In this task, a special emphasis is placed on reducing reliance on materials with a high supply risk, such as rare earth elements.</li><li>Creation of a parametric life cycle assessment model that combines life cycle assessment and optimization-based design to minimize a single-score environmental impact. This model offers insights into the environmental performance of product design and underscores the importance of minimizing environmental impact throughout a product's life cycle.</li><li>Integration of a life cycle costing model, incorporating techno-economic assessment and total cost of ownership perspectives, into the parametric life cycle assessment and optimization-based design models. This model is used to minimize levelized production and driving costs, shedding light on the trade-offs within this family of cost metrics and the optimization of manufacturing systems for motor production.</li><li>Proposal of a circular economy model/algorithm to assess the advantages of integrating the circular economy paradigm during the early design phase. All the mentioned objective functions are considered to study the impacts of applying the circular economy paradigm.</li></ul><p dir="ltr">The contributions of this research can be summarized as follows:</p><ul><li>Utilized a diverse array of analytical methodologies to parameterize the design process of a motor, incorporating the integration of Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) models, as well as the incorporation of disassembly planning for informed decision-making in the early stages of design.</li><li>Proposed a generalized objective function denoted as the Supply Risk-equivalent (SR-eq.), aimed at mitigating the risks associated with the dependency on critical materials in product manufacturing.</li><li>Introduced a novel approach for visualizing non-dominated solutions within a multi-objective framework, with experimentation conducted on up to six distinct objectives.</li><li>Substantiated the significance of decarbonizing the electric grid while maintaining competitive cost structures, the importance of advancing non-destructive evaluation (NDE) procedures for assessing the condition of end-of-life (EoL) subassemblies, and optimizing the collection rate of EoL motors.</li></ul><p dir="ltr">Demonstrated that the optimization of technical metrics as surrogate indicators for economic and environmental performance does not necessarily yield designs that are concurrently optimal in economic and environmental terms.</p>