Advancing Repairability in Consumer Electronics

Abstract

This dissertation sets out to strengthen the role of repair within the circular economy by filling critical knowledge gaps in the design and assessment of consumer electronic products. Its overarching aim is to develop design guidelines and evaluation methods that improve fault diagnosis, disassembly assessment and repairability scoring, thereby enabling longer product lifetimes and supporting right to repair policies.

To fulfill this aim, this dissertation combines three complementary research activities. First, an in-depth observational study followed 24 participants, with and without prior repair experience, while they diagnosed faults in four common appliances and verbalized their reasoning. This qualitative data was supported by video analysis and post-task interviews. Second, more than ten thousand timed repair actions carried out by professional technicians on fifty-two appliances fed a quantitative model that links specific disassembly and reassembly operations to realistic proxy times, yielding the DaRT model (Disassembly and Reassembly Timing). Third, two successive studies compared six widely used repairability scoring systems against state-of-the-art design literature and then tested three of them empirically on sixteen products, comparing proxy-time and step-count approaches and probing best- and worst-case interpretations for each scoring systems.

Findings show that product architecture shapes user success in fault diagnosis more strongly than prior repair expertise. Clear visual or auditory feedback, component visibility, and unobstructed access prompt a direct or “pinpointed” search strategy, whereas hidden fasteners and recessed modules push users toward trial-and-error and early abandonment. Disassembly difficulty emerged as one of the main barriers that makes most people give up the diagnostic task. These insights were translated into a set of design guidelines that extend conventional principles of modularity and accessibility with new emphases on facilitating testing and providing component-level fault cues.

The DaRT model was able to predict real disassembly times for vacuum cleaners, washing machines and televisions with high accuracy while remaining easier to apply than complex methods such as eDiM. By explicitly including reassembly, DaRT provides a fuller picture of ease of a complete repair cycle. Validation against independent product assessment confirms accuracy.

Analysis of existing scoring systems revealed that most scoring systems weigh ease of disassembly appropriately but treat other decisive criteria such as spare-part price, diagnostic information and safety too sparsely or with ambiguous wording. In scenarios where repair is deemed infeasible or too expensive, the research demonstrated that the current scoring systems do not accurately represent the actual repairability of products. To address this issue, the study proposed the implementation of a limiting factor approach for criteria that determine the feasibility of repair. Proxy-time metrics like DaRT correlated more closely with measured effort than simple step counts, recommending a shift toward time-based assessment in future scoring systems with more weight on physical repairability of products.

This dissertation advances scientific understanding of repairability by emphasizing the critical yet underexplored role of fault diagnosis within product design and user interaction, presenting a holistic perspective that bridges technical elements with user cognition and behavior. It refines existing repairability assessment frameworks by highlighting gaps such as inadequate coverage of diagnostic aids and inconsistent weighting criteria, proposing improvements that enhance assessment validity and reliability. Moreover, this research introduces the DaRT proxy time model as a practical, accurate alternative to complex existing metrics, beneficial across diverse product categories. Societally and environmentally, this work supports the right to repair movement by empowering users to confidently diagnose and repair devices, thereby reducing electronic waste, informing purchasing decisions, and enabling manufacturers and policymakers to create genuinely repairable, sustainable products aligned with broader climate and circular economy goals.