The increasing number of end-of-life (EOL) products has raised new challenges for sustainable manufacturing, especially when recycling efficiency, structural modularity and worker well-being must be considered simultaneously. From the perspective of symmetry and asymmetry in mechanical product design, this study proposes a Design for human-centric Modular Recycling (DFHMR) approach to improve EOL product recycling while reducing ergonomic risks in disassembly operations. In the proposed framework, functional similarity, structural correspondence and spatial association among components are used to characterize symmetry-oriented modular relationships, whereas asymmetric factors such as disassembly difficulty, carbon emissions, recycling profit and worker-related ergonomic risks are incorporated to describe the heterogeneity of practical recycling processes. A multi-objective optimization model is developed to maximize green disassembly performance and intra-module relevance while minimizing inter-module coupling and human-factor risks. To solve the constrained modular design problem, an enhanced social engineering optimizer (SEO) is introduced to balance global exploration and local exploitation. A turbo reducer case study is conducted to validate the proposed model, and comparative experiments with several multi-objective optimization algorithms demonstrate the effectiveness and robustness of the enhanced SEO. The results indicate that the DFHMR framework can provide decision-makers with a set of balanced modular recycling schemes, offering a practical reference for symmetry-oriented, sustainable and human-centered mechanical design under Industry 5.0.
Peng et al. (Sun,) studied this question.