Domain-Dependent Planning Heuristics for Locating Containers in Maritime Terminals

Maritime container terminals are facilities where cargo containers are transshipped between ships and land vehicles. These terminals involve a large number of complex and combinatorial problems. One of the important problems is related to the Container Stacking Problem. A container stack is a type of temporary store where containers await further transport by truck, train or vessel. The main efficiency problem for an individual stack is to ensure easy access to containers at the expected time of transfer. Since stacks are ’last-in, first-out’, and the cranes used to relocate containers within the stack are heavily used, the stacks must be maintained in a state that minimizes on-demand relocations. In this paper, we present a set of domain-dependent planning heuristics for finding the best allocation of containers in a yard-bay in order to minimize the number of reshuffles. To this end, the problem is distributed into a set of subproblems in order to be solved more efficiently. The resultant configuration of the yard will satisfy a set of constraints such as balanced bays, minimum distance for dangerous containers, etc.