A multi-objective mathematical model and NSGA-II algorithm for a bi-echelon supply chain with disruption risk and perishable commodities

Designing supply chains considering operational and disruption risks can bring substantial competitive advantages. Supply chains are exposed to a wide range of disasters including natural disasters, strikes, and terrorist attacks, which pose a risk to suppliers and the entire supply chain. Therefore, institutions need to improve their management strategies to respond quickly to unexpected events in the supply chain to eliminate or reduce the adverse effects of unexpected events. In this paper, a scenario- based model by scenario generation and disruption profiling is proposed to design a bi-echelon supply chain network. The developed model is validated through randomly generated examples. The Epsilon constraint approach is utilized in order to solve examples in small sizes in GAMS computer program providing exact solutions. The computational results show that the exact solution leads to lower quality results and higher computational time. However, the NP -hard nature of location-allocation problems has lead us to present a NSGA- II algorithm in order to solve the examples with large sizes. Numerical results demonstrate that designing supply chains without considering operational and disruption risks is really misleading.