Green product family design with low-carbon postponement fulfilment: A bilevel interactive optimization approach

Abstract

In the globalization process, postponement is still an effective strategy for enterprises to reduce supply chain risks and uncertainties. The enterprises must additionally consider low-carbon issues in product development process with the increasing environmental concerns. The inherent coupling of product design and postponement fulfillment that considers environmental concerns necessitates joint optimization of green product family (GPF) design and low-carbon postponement (LCP) fulfillment. However, existing literature tends to aggregate the postponement and environmental concerns into a single-level and all-in-one optimization problem based on the assumption that a (fixed) GPF architecture is pre-determined at the outset. Different from existing modes, this article proposes a bilevel interactive optimization (BIO) approach to reveal the hierarchical interactions and complex decisions involved in GPF design and LCP fulfillment. Based on bilevel programming theory, a non-linear BIO model consisting of an upper-level GPF design problem and two lower-level LCP fulfillment problems is established. A nested genetic algorithm is developed to solve the proposed BIO model. A case study of LCP manufacturing of a green electric vehicle product family is adopted to verify the feasibility and superiority of the BIO approach for the GPF design and the LCP fulfillment. Some important managerial insights are derived from the comparison experiments and the sensitivity analysis on the proposed demand postponement parameter.