Optimizing the Crane’s Operating Time with the Ant Colony Optimization and Pilot Method Metaheuristics

The container retrieval problem (CRP) is a practical problem, as it enables high operational efficiency in a container terminal system. The CRP involves finding an optimal sequence of operations for the crane, making it possible to retrieve all the containers from the bay according to a predefined order. An optimal sequence of operations is obtained by reducing the operating time of the crane. Although reducing the number of container relocations is the primary optimization goal currently discussed in the literature, minimizing the crane’s operating time is best suited for assessing the operational efficiency of the crane. Besides, as it has been already reported in previous studies, minimizing the number of relocations does not ensure the solution with the minimum operating time. In addition, little attention has been devoted to the investigation of adopting ant colony optimization (ACO) to minimize the crane’s operating time. Therefore, this study proposes a heuristic algorithm, an ACO algorithm, and a pilot method algorithm for the CRP, with a focus on minimizing the crane’s operating time. The computational experiments show that the proposed algorithms have produced better solutions in comparison with leading algorithms from the literature.