The solar industry is one of the fastest-growing energy industries in the global market. The reason is a combination of the falling prices of modules and inverters and increased conversion to fossil-free energy production. When a photovoltaic module reaches the end of its life it needs to be replaced and discarded, which can create a sustainability problem depending on how this is managed. Today, less than 10% of the global photovoltaic waste is recycled. Only the European Union has implemented photovoltaic waste regulations in the form of the WEEE Directive, which requires that 85% of the waste is collected and at least 80% of waste collected must be prepared for reuse or recycling. This master thesis examines the energy technical, economic, and political conditions for a Swedish photovoltaic recycling plant. This is done through a literary study that is enhanced with calculations of future potential waste volumes and their economic value. As an alternative to a Swedish plant, the energy consumption for transporting waste to existing recycling plants in Europe is evaluated. The photovoltaic technologies included in this work are silicon-based mono-and polycrystalline modules, cadmium tellurium (CdTe) and copper indium gallium selenide (CIGS). Based on the calculations and the literature study, the energy technical conditions are good and not a barrier for a potential facility, the political conditions are deficient, and regulations need further development. The economic conditions constitute the largest barrier as waste volumes are not large enough for a Swedish facility to be economically profitable until 2042. The energy consumption for transport to existing recycling plants in Europe was 22 MJ/module for silicon-based mono-and polycrystalline modules and 10 MJ/module for CdTe modules. Which is a good alternative to a Swedish plant as collection processes and recycling processes are already in place.

Recent efforts mitigating the global energy crisis has led to a radical shifttowards solar energy production. However, photovoltaic module (PVM) waste remains a grave concern. Burden shifting within a system is attributed to the lack of systems thinking applied in socio-technical transitions. Policies describe the processes for end-of-life management such as recycling, yet in practice leaves room for improvement. This paper aims to aid decision-makers with a systems perspective examining the barriers to increased recycling of PVMs. A comparative case study using qualitative data was collected from 12 semi structured interviews in South Africa and Sweden. Interviewees were recognized as key actors in the solar energy transition, as well as having a role to play in recycling PVMs. Using systems thinking approach, the interview results were used to define and visualize a social-technological-ecological system (STES), as well as its components and their relationships contained therein. The STES for Sweden included 12 components with 15 different relationships. Whereas South Africa’s systems included 13 components and 25 different relationships, owing to the addition of the ‘Social equity’ component and several more relationships within the social subsystem, extending to the technological subsystem. Barriers, where connections between components were disconnected, were interpreted. Despite the stark contrast between South Africa and Sweden’s landscapes and regimes, the pathways to bridge barriers are relatively the same. These include implementing economic instruments to encourage recycling, circular design of PVMs, and enhancing the information, knowledge and skills of recycling processes. The transition’s maturity was an overarching theme influencing the broader state of the system. Further research on the cognitive dissonance of sustainability transitions and the long-term impacts, as well as cause and effects relationships between components, and refining component definitions in the social subsystem based on emerging literature are encouraged.

The operation and maintenance phase of a complex technical system may deal with strategicdecisions for asset retirement and end-of-life management. When a fleet of aircraft reachesthe retirement phase, the operation of remaining fleet should still be kept at a defined level ofavailability. Obviously, the provisioning of spares is a key issue to support the maintenanceand operation of the remaining fleet. The best practice within the aviation industry is to re-usethe spares of retired aircraft to support the operational fleet. This is referred to parting-out.The purpose of the research conducted for this thesis has been to develop decision supportmethodologies, models and tools for the management of a sustainable part-out-based sparesprovisioning for an aircraft fleet during its retirement period. The proposed methodology willbe used to support the retirement process of aircraft fleet and enhance the organisation’scapability of making efficient and cost-effective decisions concerning the re-use of spare partsduring the retirement period. To achieve the purpose of this research, literature studies, casestudies, algorithm development and simulations have been conducted. Empirical data havebeen collected through document studies, interviews, and the perusal of archival records fromSaab Support and Services AB. The data analysis performed for this research has been basedon theories and methodologies within reliability analysis, cost modelling, spares forecasting,stock provisioning and decision making, in combination with the best practices implementedby the aviation industry for the end-of-life management and retirement of aircraft.In the present thesis, part-out-based spares provisioning (PBSP) program is proposed to utiliseretired aircraft units effectively as spare parts. The proposed approach is illustrated andverified through a case study performed on the “Saab-105” military aircraft fleet withinSwedish air force fleet. A PBSP programme is proposed, associated management activitiesare described, the key decision criteria are presented, and a functional framework for aneffective PBSP is suggested. The proposed PBSP program provides a foundation for furthermeasures and tasks to be performed within the retirement period, such as terminatingmaintenance contracts, discarding internal maintenance capabilities, reviewing stocks, scalingdown administrative processes (e.g. spares procurement and obsolescence monitoring), etc.An important part of the PBSP programme is the reliability analysis of multiple repairableunits, and this has been investigated, using parametric and non-parametric reliabilityapproaches. The aim is to identify a practical approach for estimation of the future sparedemand at fleet level. Furthermore, a set of computational models and search algorithm havebeen developed for the identification of applicable termination times, of both the parting-outprocess and the maintenance and repair actions performed on the units. This includestermination of the parting-out process (PO), the sending of parted-out units directly to storage(POS), and repair actions performed on the units received at the repair shops owing tocorrective (CM) and preventive (PM) maintenance, as well as the parted-out units that need tobe repaired (POM). The feasible termination alternatives are compared with regard to theirrespective costs and the most cost-effective solutions are identified.The results of the research study show that a PBSP programme can yield large reductions inmaintenance and spares procurement costs, while supporting operation of existing fleet athighest required availability. It also contributes positively to implement a green supply chainduring the retirement phase. The methodology and approaches introduced within the thesiscan be applied in other civil applications, such as energy, mining, process industry andtransportation sectors.

Cette thèse fournit des clés pour mesurer, améliorer et piloter la performance de circularité de produits industriels à différentes échelles d’implémentation de l’économie circulaire (micro, meso, macro). Plusieurs indicateurs de circularité y sont expérimentés au travers d’un cas d’étude industriel et une analyse critique de ces indicateurs est effectuée au regard, entre autres, du paradigme de l’économie circulaire, et de leur intégration dans les pratiques industrielles de (re)conception et développement de produits et services. Dans le même temps, en réponse au nombre croissant d’indicateurs de circularité développés, de périmètres et d’ambitions inégales, une taxonomie d’indicateurs de circularité est proposée dans le but de clarifier le flou actuel autour de cette nébuleuse d’indicateurs de circularité. Cette classification ordonnée d’indicateurs est accompagnée de son outil informatique d’aide à la sélection afin de faciliter leurs usages appropriés. Un nouvel indicateur de circularité est également développé et expérimenté, puis des recommandations pour le développement d’indicateurs futurs sont discutées. Bien que les indicateurs évoqués dans la thèse aient pour vocation à être utilisés pour tout type de secteur, l’industrie des véhicules lourds en est le cadre d’application. En effet, en l’absence de réglementation européenne sur la fin de vie de ces véhicules, il s’agit d’identifier, de questionner et de tester les leviers d’actions que cette industrie peut activer pour améliorer sa performance dans une perspective d’économie circulaire.Tout d’abord, les meilleures pratiques et les défis actuels de l’industrie des véhicules légers et des véhicules lourds sont mis en exergue au regard des quatre pierres angulaires de l’économie circulaire définis par la Fondation Ellen MacArthur (conception circulaire, nouveaux modèles d’affaires, logistique inversée, écosystème) et des quatre boucles principales du modèle circulaire (maintenance, réutilisation, reconditionnement, recyclage). Ces pratiques exemplaires sont synthétisées au sein d’un guide de deux pages pour faciliter leur diffusion et adoption par les praticiens industriels désirant mettre en oeuvre de tels modèles de circularité. Par la suite, une étude industrielle pilote a été menée avec un constructeur d’engins de manutention cherchant à développer son activité de reconditionnement d’engins en fin de vie. Inspiré par des investigations sur le terrain couplé à un état de l’art étendu, une modélisation multi-échelles – a) engin et composants clés, b) processus de démantèlement, c) filières de valorisation – a permis (i) de proposer et de valider une amélioration (en temps et en ressources) des opérations de démontage d’un point de vue organisationnel et technique, (ii) d’effectuer une analyse économique et environnementale des activités de démantèlement et de valorisation. Un premier outil d’aide à la décision a également été conçu pour accompagner l’industriel dans la valorisation optimale de son engin en fin de vie. Des réflexions sur la généralisation et transposition des approches développées à d’autres engins ou secteurs sont données, ainsi que des pistes de recherche prometteuses pour accomplir davantage la transition vers une économie circulaire – effective, efficiente et durable. / Implementing circular economy practices is increasingly acknowledged as a convenient solution to meet the goals of sustainable development. Meanwhile, there is at present no recognized way of measuring how effectively a region or a company is in making the transition to a circular economy, nor holistic monitoring tools for supporting such a process. New methods and tools are required to support industrial practitioners in their transition towards more circular practices, as well as to monitor the effects of circular economy adoption. In absence of regulations addressing the end-of-life management of their fleet, the heavy vehicles industry is both a challenging and promising industrial sector – of huge economic and environmental importance, but barely addressed from a research perspective – that needs to be boosted in its move to a more circular economy. An in-depth preliminary study reveals indeed huge potential to develop circular strategies and solutions in the heavy vehicles sector. This research explores the improvement potential for closing industrial material and components loops.On this basis, the objectives of the present Ph.D. thesis are: to provide an integrated and comprehensive framework to measure, improve and monitor the circularity performance of complex industrial systems; to identify the best mechanisms and action levers to close the loop on heavy vehicles and associated key components - providing thus decision-making support for the end-of-life management of heavy vehicles. At the intersection of design engineering and industrial ecology, this Ph.D thesis - by articles - aims to provide new meaningful insights both for academics and industrial practitioners. In fact, for each chapter, academic publications and industrial deliverables are given, illustrating and disseminating both theoretical contributions and practical implications. For instance, it includes: a proposed taxonomy of circularity indicators and its associated selection tool; an experimentation and critical analysis of several circularity indicators on a heavy vehicle’s key component; the design of a multi-tool methodology to model, simulate and quantify the impact of potential circular strategies; an industrial pilot study on an end-of-life heavy vehicle, dealing with the techno-economic and environmental analysis of possible recovery options.

The changing climate is a major driver for transitioning towards a Circular Economy (CE). However, conceptual discussions and business models related to CE are still emerging, thus considered to be inadequate and immature. One way to promote and accelerate a CE is through shifting towards Circular procurement (CP). Additionally, one major change needed for procurement in order to become circular, regards the assurance of follow-up and control of products and materials. However, there is limited research on CP in terms of collaboration and follow-up activities. Thus, this study explores how collaboration between an organization, its suppliers and customers can be strategically handled to support follow-up and control of products and materials within CP.  The chosen methodology consisted of a qualitative research design with an exploratory approach. A total of eleven semi-structured interviews were conducted. Derived from the theoretical findings coupled with empirical findings, a framework was developed to clearly map out the challenges related to CP, activities needed in procurement when transitioning to a CP as well as the potential outcomes of these. To ensure the relevance of the activities included in the developed framework, three out of the total eleven interviews were conducted with experts within the circular field, to validate the framework. In terms of the findings of this research, several important aspects related to how collaboration can promote integration of circularity within procurement to ensure follow-up and control of products and material were found. Firstly, a new type of internal collaboration between sales and the procurement department is needed. Besides this, the procurement function should focus on maintaining a long-term relationship with the suppliers, preferably already contracted ones. Further, due to the lack of knowledge related to the concept of CP, it was found that there is a need to integrate a preparation phase called phase 0 prior to the traditional steps of a procurement process. Finally, it was found that the integration of feedback and monitoring mechanisms, in form of documentation and checklists, is of importance to monitor and evaluate circular targets as well as document the lessons learnt to apply these in upcoming procurement processes. / Det förändrade klimatet är en viktig drivkraft för övergången till en Cirkulär Ekonomi (CE). Konceptuella diskussioner och affärsmodeller relaterade till CE håller fortfarande på att växa fram, och anses därför vara otillräckliga och omogna. Ett sätt att främja och påskynda en CE, är att växla mot cirkulära inköp (CI). En stor förändring som krävs för att inköpsfunktionen ska bli cirkulär, är att säkerställa uppföljning och kontroll av produkter och material. Dock finns det begränsad forskning om CI vad gäller samverkan och uppföljningsaktiviteter. Således undersöker denna studie hur samverkan mellan en organisation, dess leverantörer och kunder kan hanteras strategiskt för att säkerställa uppföljning och kontroll av produkter och material inom CI. Den valda metodiken bestod av en kvalitativ studie med ett utforskande förhållningssätt. Totalt genomfördes elva semi-strukturerade intervjuer. Med utgångspunkt från litteraturgenomgången tillsammans med analysen från insamlade data utvecklades ett ramverk för att tydliggöra utmaningar relaterade till CI, aktiviteter som behövs inom inköpsprocessen vid integration av cirkularitet, samt det potentiella resultatet och påverkan av dessa. För att säkerställa relevansen av aktiviteterna ingående i det utvecklade ramverket, genomfördes tre av de elva intervjuerna med experter som innehar kunskap kring cirkularitet. Syftet med dessa tre intervjuer var huvudsakligen för experterna att validera ramverket. När det gäller resultaten av denna studie hittades flera viktiga aspekter relaterade till hur samverkan kan främja integration av cirkularitet inom inköpsprocessen för att säkerställa uppföljning och kontroll av produkter och material. För det första upptäcktes behovet av en ny intern samverkan mellan sälj och inköpsfunktionen. Utöver ökad kommunikation och samverkan mellan sälj och inköpsfunktionen, bör inköpsfunktionen fokusera på att upprätthålla en långsiktig relation med leverantörer. Vidare, på grund av bristen på kunskap relaterad till begreppet CI, fann man att det finns ett behov av att integrera en förberedelsefas som i denna studie kallas fas 0, före de traditionella stegen i en inköpsprocess. Slutligen fann man att det är viktigt att integrera återkopplings- och uppföljningsmekanismer i form av dokumentation och checklistor, för att kunna övervaka och utvärdera cirkulära mål samt dokumentera lärdomarna för att tillämpa dessa i kommande inköpsprocesser.