An iterative three-stage algorithm for the pre-marshalling problem in container terminals

The pre-marshalling problem converts an initial layout of a bay into a desired final layout in which no higher-priority containers with smaller container type are buried under those with larger container type. After defining different clusters and groups of containers, an iterative three-stage algorithm is proposed to this problem: in the first stage, a local optimization is applied; in the second stage, one stack is selected and then emptied out; and in the third stage, the emptied stack selected in the second stage is refilled. Public data is applied to compare our algorithm with the existing ones in literature, and the experiment results show that our algorithm outperforms others in terms of the number of re-handling movements.