Coordinated optimization of low-carbon product family and its manufacturing process design by a bilevel game-theoretic model

While increasing environmental issues arising from product development and manufacturing activities have attracted much attention from both academia and industry alike, few researches have addressed joint optimization of product family architecting (PFA) and its manufacturing process configuration (MPC) considering environmental concerns. Moreover, the hierarchical characteristics underlying these two optimization problems and complex interactions among PFA, MPC, and environmental concerns are failed to be revealed and addressed in the previous research. In this paper, a bilevel game-theoretic model for coordinating low-carbon PFA (L-CPFA) and low-carbon MPC (L-CMPC) is proposed. The L-CPFA decision by a designer (game-leader) is represented as an upper-level optimization problem for optimal configuration of module instances and architecture of compound modules and product variants from the perspectives of economic and environmental performances. The L-CMPC decision by a manufacturer (game-follower) is modeled as a lower-level optimization problem in order to determine the optimal low-carbon realization process planning of each primitive module, each compound module, and the assembly and transportation mode of each product variant according to the upper-level decision. A nonlinear, 0-1 integer bilevel programming model is developed, and then solved by a nested bilevel genetic algorithm (NBGA). A case study of a microwave oven product family is presented to demonstrate the feasibility and potential of the proposed model and algorithm. The results indicate that the carbon emissions have apparently impact on the optimal PFA and MPC decisions, and integrating low-carbon awareness into product family development activities is beneficial and advisable for enterprises to increase customer-perceived utilities and competitive advantages. Our proposed model can handle well the conflict and coordination between L-CPFA and L-CMPC, and balance well enterprise's benefits with environmental impacts triggered by development activities.