A two-phase heurist algorithm for the capacitated location-routing problem

The capacitated location-routing problem (CLRP) belongs to the field of logistics of transportation. The CLRP appears as a combination of two difficult problems: the facility location problem (FLP) and the vehicle routing problem (VRP). It is a NP-hard problem. In order to solve practical large scale capacitated LRP, We propose a two-phase approach to solve the CLRP. The approach is based on simulated annealing (SA) and ant colony algorithm (ACA). In the first phase of the proposed algorithm, a simulated annealing is performed on the location variables to determine the location of facilities and the allocation of customer to the facilities. In the second phase, in order to obtain a good routing for the given configuration, an improved ant colony algorithm (IACA) is proposed for the capacitated vehicle routing problem (CVRP). To compare the proposed algorithm with other heuristic algorithms, a series of computational experiments are done on randomly generated test problems. The simulation results demonstrate that the above approach is feasible and efficient. © 2009 Binary Information Press.