Loading sequencing with consideration of container rehandling

During the loading operations in container terminals, the handling time of yard cranes for retrieving a container depends on the stacking relationship between containers, which changes once rehandling occurs. Since rehandling is hard to be prevented in practice, the handling time (especially the setup time) of yard cranes for each container is dynamically changing. This research takes this dynamic property into consideration whereas previous work generally considered the handling time is deterministic. A mathematical model is constructed for this problem. An algorithm based on Greedy Randomized Adaptive Search Procedure (GRASP) is developed. The numerical experiments show the effectiveness and efficiency of the proposed algorithm. In addition, the cases with and without consideration of rehandling have been compared through numerical experiments.