The global unsustainable production and consumption patterns in the fashion and textile industry are a prevailing problem. With the rising trend of European brands reshoring their textile manufacturing and upcoming circular economy frameworks from the EU, the Turkish textile industry may face pressures to transform towards circularity in order to remain competitive. To address the research gap concerning prevalent challenges to implement circularity principles in the critical stage of product design, the purpose of this thesis is to explore the barriers to adopting circular product design in the Turkish textile sector from a manufacturers perspective. This study was conducted in Istanbul with eleven textile and apparel manufacturers of different kinds. To reach a nuanced understanding of each perspective, a qualitative research methodology, through semi-structured interviews with factory managers, was used. The empirical findings of barriers are categorised as internal (financial, responsibility, knowledge) and external (country- and industry-specific). Major internal barriers include prioritising profits over circularity, prioritising customer demand over circular design, and unfamiliarity with key concepts. Country-specific external barriers include lack of competent personnel in Turkey and harsh taxation policies. Industry-level barriers include insufficient resources, limited control over fast-fashion demands, and lack of innovative technologies. This thesis contributes to an increased understanding of the scarcely researched topic and enables practitioners to develop efficient policies and business strategies to ease sustainable business development. Future research is suggested to explore drivers and strategies to apply circular product design within the Turkish textile industry. Additionally, further research can be conducted where this study is replicated but from the perspective of brand retailers with procurement operations in Turkey.

This thesis aims at developing a (dis/re)assembly oriented methodology towards product end-of-life. Particular focus in this thesis is on the circularity of furniture via design for (dis/re)assembly. The main motivation behind this study was the need for a method to evaluate the (dis/re)assembly options of furniture designs to be able to facilitate repair, reuse, remanufacturing, refurbishing, or recycling. The study draws upon relevant theories and prior research on Circular product Design, Design for EoL, Design for Environment, and Design for (Dis)assembly of vehicles, electrical and elocronic equipments, whitegoods, as well as office furniture, though relatively limited. The proposed methodology determines major aspects of design for (dis/re)assembly to be taken in to consideration in the early stages of product development. It further provides a set of parameters that are relevant to cabinet type and upholstery furniture group. The study involves a variety of qualitative research methods that are embedded in an interactive research conduct with the engagement of different stakeholders that are charged with the task of product development at Ikea of Sweden (IoS), the collaborator of this study.  The proposed methodology is implemented on three selected furniture designs in a pilot study. The results of the study, above all, suggest that (dis/re)assemblability of a product is a strategic choice that needs to be made at early phases of product development, namely the design phase. Two particular features of the furniture groups, upon which this study focuses, emerges as factors having negative impact on the disassemblability of products: first, wooden frame sofas with respect to their complex structure and connectivity of componants and, second, permanent joints with respect to their destructive impact on the product. The study concludes that it is feasible to develop and implement a potentially comprehensible method to evaluate the ease of disassembly of furniture products and to design for disassembly. The proposed methodology in this study is a contribution to support product design for disassembly towards product circularity.

This thesis investigates the manifestations of circular business models and circular product design strategies in the Swedish clothing industry, using a multiple case study approach that examines five Swedish clothing companies. Guided by the first research question: What are the current circular product design strategies and circular business model strategies for companies operating in the Swedish clothing industry? the findings reveal an emphasis on circular product design strategies compared to circular business models, among the studied clothing companies. Prominent product design strategies encompass timeless and adaptable designs, utilization of high-quality materials, rigorous product testing, and a focus on minimizing components, while permanent collections and standard spare parts are less frequently used. Regarding circular business models, the study reveals an adoption of strategies such as repair, reuse, internal upcycling, and recycling. Conversely, approaches such as clothing rental- and subscription services, secondhand- and repair services as well as collaborations for repair and refurbishment are employed to a lesser extent.  In addition, the study explores the influencing factors that determine the adoption or non-adoption of these circular approaches, guided by a second research question: What are the factors that influence the companies to adopt, or not to adopt circular product design strategies and circular business model strategies? The study reveals that the companies prioritize producing durable goods, but that challenges emerge in achieving a balance between circular objectives and material quality, without compromising either aspect, especially within childrenswear and workwear that has certain requirements. Despite these challenges, the companies both exhibit a commitment to integrating circular practices into their operations, aswell as show a willingness to explore new and innovative circular product design concepts, including increased utilization of mono- and recyclable materials. Another significant challenge lies in the alignment of circular business models with existing organizational practices, which requires substantial organizational transitions. However, permanent collections are found to be a potential facilitator for circularity within the clothing industry, as it allows for comprehensive testing, feedback loops, streamlined supply chains, things of which could enable better opportunities for both circular product designs, and circular business models such as repair- and secondhand services. The study highlights future trends in circular business models, including a focus on repair services, secondhand offerings, and enhanced recycling practices. The research contributes to the understanding of the adoption of circular strategies in the clothing industry and underscores the need for further investigations into the influencing factors at play and the implications across international contexts. / Denna avhandling undersöker strategier för cirkulära affärsmodeller och cirkulär\\ produktdesign inom den svenska klädindustrin, genom att använda en flerfallsstudie som undersöker fem svenska klädföretag. Med utgångspunkt i forskningsfrågan: Vilka är de nuvarande cirkulära produktdesignstrategierna och cirkulära affärsmodellstrategierna för företag som är aktiva inom den svenska klädindustrin? visar resultaten en tyngdpunkt på cirkulära produktdesignstrategier jämfört med cirkulära affärsmodeller, bland de studerade klädföretagen. De främsta produktdesignstrategierna omfattar tidlös och anpassningsbar design, användning av högkvalitativa material, omfattande produkttester och ett fokus på att minimera antalet komponenter, samtidigt som permanenta kollektioner och standardiserade reservdelar användsmer sällan. När det gäller cirkulära affärsmodeller visar studien att strategier som reparation, återanvändning, intern upcycling och återvinning används. Däremot används strategier som uthyrning av kläder och prenumerationstjänster, secondhand- och reparationstjänster samt samarbeten för reparation och renovering i mindre utsträckning.  Vidare undersöker studien de påverkande faktorer som avgör om dessa cirkulära strategier antas eller inte. Detta besvaras med hjälp av en andra forskningsfråga: Vilka är de faktorer som påverkar företagen att anta, eller inte anta, cirkulära produktdesignstrategier och cirkulära affärsmodellstrategier? Studien visar att företagen prioriterar att producera hållbara produkter, men att det finns utmaningar med att uppnå en balans mellan cirkulära mål och materialkvalitet, utan att kompromissa med någon av aspekterna. Detta gäller i synnerhet barnkläder och arbetskläder som har särskilda krav. Trots dessa utmaningar visar alla studiens företag både ett engagemang för att integrera cirkulära metoder i sin verksamhet och en vilja att utforska nya och innovativa cirkulära produktdesignkoncept, inklusive ökat utnyttjande av mono- och återvinningsbara material. En annan stor utmaning ligger i att anpassa cirkulära affärsmodeller till befintliga organisatoriska rutiner, vilket kräver omfattande organisatoriska förändringar. Permanenta kollektioner har dock visat sig vara en potentiell facilitator för cirkularitet inom klädindustrin. Detta mot bakgrund av att permanenta kollektioner möjliggör omfattande tester, feedbackloopar och effektiviserade leveranskedjor, vilket kan ge bättre möjligheter för både cirkulär produktdesign, och cirkulära affärsmodeller som reparations- och secondhand-tjänster. Studien visar att framtida trender inom cirkulära affärsmodeller inkluderar ett fokus på reparationstjänster, secondhand-erbjudanden och förbättrad återvinning. Dessutom bidrar studien till en förståelse av hur cirkulära strategier inom klädindustrin kan tillämpas. Slutligen understryker studien att framtida studier bör utvärdera samtliga faktorer som påverkar tillämpningen av cirkulära strategier i klädindustrin, samt hur dessa kan variera ii nternationella sammanhang.