Variant-Level Interface Standardization Methodology for Complexity Reduction in Product Family Design

Abstract

Abstract. Managing design complexity is a critical challenge in modular product families, especially when diverse module variants must be combined via standard interfaces. This study proposes a methodology for interface standardization in modular product families by modeling design relationships at the module variant level. Unlike conventional approaches that assume fixed or single interfaces, the proposed framework explicitly considers multiple interface configurations and their impact on design complexity. Two types of complexity are defined: standardization effort, which refers to the coordination effort required to develop standard interfaces, and integration effort, which reflects the structural complexity arising from integrating module variants with interfaces. Based on these measures, the interface design problem is formulated as a decision framework that balances the trade-off between standardization and integration efforts. A case study on an automotive front chassis system demonstrates the applicability of the approach, showing how different interface configurations lead to distinct complexity outcomes and how Pareto-efficient solutions can be identified. The results provide practical insights into interface design strategies, highlighting that the optimal level of standardization depends on the dominant source of complexity.