Abstract
This study proposes a need-driven framework for the modular design of functional armchairs for young adults living alone. It aims to establish a systematic linkage among user-need priorities, functional organization, and product architecture generation. User needs were collected through observations, interviews, and questionnaires, leading to the identification of 15 core functions. These functions were transformed into 11 functional modules using function-structure mapping, correlation assessment, and hierarchical clustering. AHP was applied to determine evaluation weights, and TOPSIS was used to compare design alternatives. The results show that the optimized solution better aligns with user expectations in both functionality and experience. The study contributes a need-to-module translation mechanism that positions modularization as an intermediate decision layer between need prioritization and product implementation. This framework establishes a traceable pathway linking user needs, module generation, and design evaluation, offering methodological support for complex product design.