THE OPEN LOCATION-ROUTING PROBLEM FOR MULTI-OBJECTIVE OPTIMIZATION OF SUSTAINABLE SUPPLY CHAIN CONSIDERING SOCIAL CONCERNS

Taking into account the variety of real-world constraints and in-corp orating them into classical problems are essential in designing supply chain networks. Meanwhile, given the importance of outsourcing, the open location-routing problem (OLRP) is proposed to fulfill customers' demands and mini-mize costs by determining the optimal location of vehicle facilities and routes. In addition, supply chain sustainability is attracting increasing attention since it promotes a bright future for the coming generations by striking a balance between economic, environmental, and social performances in supply chain design. In this study, we contribute to the scarce literature on supply chain sustainability and OLRP. First, using OLRP, we model a sustainable supply chain that addresses all sustainability pillars. Second, we use the NSGA-II meta-heuristic method to solve the proposed model and finally compare its ef-ficiency with Cplex. The model characterized in this study can be considered a basic reference on the subject of supply chain sustainability and OLRP. More-over, we indicate that both of the proposed solution methods are capable of solving the developed model; however, the meta-heuristic method, NSGA-II, is significantly more efficient than the classical one, Cplex, in terms of compu-tation time, particularly in solving medium-and large-scale problems.