Problem of Modeling Global and Closed-Loop Supply Chain Network Design

Nowadays, the economic activities cause some environmental problems for not only the global warming by Greenhouse Gas (GHG), but also the material starvation by mass consumption of resources. In order to resolve their problems simultaneously, Japanese government took effect with the plastic regulation and announced that GHG emissions became zero by 2050. In order for manufacturing companies to develop sustainably, they are required to design the Global Closed-Loop Supply Chain (GCLSC) network to recycle End-of-Life (EOL) products and reduce GHG emissions. The GCLSC network integrates the global supply chain network, which is a series of cross-border transaction of product, and the local reverse supply chain network, which is a domestic transaction for collecting and recycling EOL products. However, it is necessary to select appropriate global suppliers considering GHG emissions because the amount of material-based GHG emissions in EOL product is dependent on manufacturing country. On the other hand, the GCLSC network is costly for procurement, manufacturing, transportation, recycling and opening facilities costs. Thus, the decision maker who designs designing GCLSC network should consider not only cost, but also environmental aspects such as recycling EOL product and GHG saving weight simultaneously. This study designs the GCLSC network to minimize total cost and to maximize entire recycling rate on global and local supply chain network. Furthermore, the GHG emission from components procurement and the GHG saving weight by recycling EOL product is evaluated. First, the GCLSC network is modeled. Next, the objective function for minimizing total cost and maximizing entire recycling rate are formulated with integer programming. Finally, a numerical experiment is conducted and evaluated in terms of costs, entire recycling rate, and GHG emission.