Multi depots Capacitated Location-Routing Problem with Simultaneous Pickup and Delivery and Split Loads: Formulation and heuristic methods

Problems in real world include various constraints. So the reliable models should be designed that satisfy the reasonable number of these constraints. These models should be applicable. In this paper، regarding the mentioned circumstances، we design a model for multi depots capacitated location-routing problem with simultaneous pickup and delivery and split loads. The paper emphasis is on the split property that happens when demand of a customer exceeds vehicle capacity. We propose a mixed integer-programming model. Also we develop two metaheuristics for solving large scale instance problems. The first approach is based on discrete genetic algorithm and continuous genetic algorithm and the second one is based on discrete genetic algorithm and particle swarm optimization. Results of solving instance problems by CPLEX solver and proposed DCGA and DGAPSO algorithms show that both algorithms are effective and DGAPSO outperforms DCGA in solution quality and computation times.