Research on ant colony optimization algorithm for the open vehicle routing problem

This paper studies the open vehicle routing problem, in which the vehicles do not return to the starting depot after serving the last customers or, if they do, they must make the same trip in the reverse order. We propose an Ant Colony Optimization metaheuristic hybridized with tabu search algorithm for the open vehicle routing problems. The proposed algorithm is a MAX-MIN Ant System hybridized with tabu search, which is implemented in the hyper-cube framework. Additionally, a post-optimization procedure is incorporated in the proposed algorithm to further improve the best-found solutions. The computational results of the proposed algorithm compared to those of other algorithms are reported. The computation results experimentally indicate that the proposed algorithm is an efficient method for solving the open vehicle routing problems.