The SHIFT 6mq project investigated how a modular smartphone can be designed, produced, and used in ways that extend its useful life while keeping its environmental footprint comparable to conventional devices. Life‑cycle assessment results show that the SHIFT 6mq’s environmental impact is in the same range as other contemporary smartphones such as Apple, Huawei, and the earlier Fairphone 2. The modularity of the device does not add significant material or energy costs because the design avoids extra housings or additional connectors; instead, it relies on plug‑and‑screw connections that replace soldered joints. This approach allows a very deep disassembly depth, enabling technicians and even motivated consumers to replace small, damaged components rather than swapping entire modules. While this can reduce the need for large, costly replacements, it also requires manufacturers to maintain a larger inventory of spare parts, and the small‑part construction may be intimidating for less tech‑savvy users. Surveys conducted during the project confirmed that clear communication of repairability positively influences do‑it‑yourself repair attempts.

The project also explored business and usage scenarios that could further prolong device life. Two representative models were quantified: a rental model (PaaS) and a cascade usage model. In the rental scenario, a defined lease period of five years is combined with scheduled battery replacements and the option to upgrade components, thereby keeping the device in service longer without increasing damage frequency. The cascade model connects users with different needs—such as families or second‑hand markets—through rapid returns and professional repair, allowing a single device to serve multiple life‑cycle phases. Quantitative estimates based on the SHIFT 6mq’s component set suggest that both models can extend overall device longevity beyond the average smartphone usage of 3–3.3 years, which is the current industry norm. The project’s data also highlight that the current repair rate for technical defects is about 52 %, yet only 40 % of devices are replaced because of such defects; most replacements are driven by a desire for newer features.

Beyond the technical and business analyses, the SHIFT 6mq project produced a comprehensive set of studies on premature obsolescence, design for durability, and user behaviour. These studies provide context for the life‑cycle assessment and help identify where design changes can most effectively reduce early replacement. The project’s findings are consistent with broader EU initiatives on circular design, such as the proposed Ecodesign Requirements for Sustainable Products Regulation and the EU’s focus on repairability and digital product passports.

Collaboration was central to the project’s success. SHIFT GmbH led the design and manufacturing of the prototype, while the Technical University of Berlin’s Transdisciplinary Sustainability Research in Electronics provided expertise in life‑cycle assessment and modular design. Leuphana University Lüneburg’s Centre for Sustainability Management contributed to the business model development and scenario analysis, and AfB gemeinnützige GmbH, a non‑profit that refurbishes used electronics, supplied practical insights into repair workflows and end‑of‑life handling. The project ran from 2021 to 2023 under the MoDeSt (Modular Design for Sustainability) framework, funded through European Union research programmes aimed at advancing circular economy practices in consumer electronics.