A feasibility-based heuristic for the container pre-marshalling problem

This paper addresses the container pre-marshalling problem (CPMP) which rearranges containers inside a storage bay to a desired layout. By far, target-driven algorithms have relatively good performance among all algorithms; they have two key components: first, containers are rearranged to their desired slots one by one in a certain order; and second, rearranging one container is completed by a sequence of movements. Our paper improves the performance of the target-driven algorithm from both aspects. The proposed heuristic determines the order of container rearrangements by the concepts of state feasibility, container stability, dead-end avoidance and tier-protection proposed in this paper. In addition, we improve the efficiency of performing container rearrangements by discriminating different task types. Computational experiments showcase that the performance of the proposed heuristic is considerable.