Growing concerns for the environment demands that product design for the life cycle (DFLC) is considered more

carefully. Modularity is seen as a means to incorporate life cycle considerations into product architecture design;

however, to date, most modular design methods concentrate on generating highly-modular product architectures but fall short in assessing life cycle consequences of these modules. This paper proposes a methodology to find a robust product modular architecture with minimal life cycle costs and environmental impacts at the design configuration stage. The primary objective of the proposed methodology is not to maximize modularity level, but to adopt life cycle costing and life cycle assessment to identify the most beneficial modular structure. In the case study presented, processing facilities are modeled as a closed-loop supply chain, and their influence on life cycle metrics is evaluated. Using the proposed methodology, a designer can identify not only the most beneficial modular structure during configuration design, but also an optimal supply chain network structure.