A beam search algorithm for the load sequencing of outbound containers in port container terminals

A beam search algorithm was applied to solve the load-sequencing problem in port container terminals. The algorithm was used to maximize the operational efficiency of transfer cranes and quay cranes while satisfying various constraints on stacking containers onto vessels. The load-sequencing problem consisted of two decision-making subproblems. In the first subproblem, a pickup schedule was constructed in which the travel route of a transfer crane as well as the number of containers it must pick up at each yard-bay are determined. In the second subproblem, the load sequence for individual containers was determined. This study suggested a search scheme in which an algorithm to solve the second subproblem is imbedded into the algorithm for the first subproblem. Numerical experiments using practical data were performed to test the performance of the developed algorithm.