Improvement the efficiency and efficiency of the closed loop supply chain: Whale optimization algorithm and novel priority-based encoding approach

With the expansion and intensification of competition, supply chain management has become one of the key issues facing economic firms, as all the activities of organizations to produce products, improve quality, reduce costs and provide services required by customers, has been affected. In this research, a closed loop supply chain network include levels of (manufacturing centers, demand zones, collection centers and disposal centers) under certainty is considered. The main objective of this paper is to determine the optimal number and location of potential facilities and determine the optimal flow considering the minimization total supply chain network cost. To solve this model, a new metaheuristics algorithm called the whale Optimization algorithm has been used with novel priority-based encoding. Also, to demonstrate the high efficiency of the proposed method, 21 sample problems were designed in small, medium and large sizes, and the results obtained from the solving method and the results obtained from the methodology for solving the subject literature were compared. Comparisons between solving methods with consideration of the two averages of the objective functions and the average computational time indicate the efficiency of the proposed solution method for the comparison of the other methods of solving.