A reward-based algorithm for the stacking of outbound containers

Abstract: As global trade increases, container transshipment activities increase rapidly. Therefore, high competition among container terminals has emerged. The decision for good stacking positions for containers plays a critical role on the performance of a container terminal, since it influences the productivity of the terminal in a strong sense. In this study, we focus on the minimization of the berthing time of vessels by improving the stacking operations through minimization of non-value-added handling operations of containers, which is called reshuffling, as well as the traveling time of the cranes operating at the storage yard. Most of the containers in the container terminal we focus are outbound, which are transported into the container terminal via external trucks and stored in the stacking yard until they are loaded onto vessels. We propose a reward-based algorithm for the stacking of outbound containers by taking the following four components into consideration; container's distance to the closest RTGC, RTGC's workload, the number of stacked containers at the neighborhood bays, and the current height of the stacks at the storage yard. The inputs of the algorithm include the relevant information of the container to be stacked that are just entered into the terminal gate, current usage information of the storage yard and the current positions of the yard cranes. The proposed stacking strategy is in implementation phase to one of the container terminals in Izmir. The results seem to be promising when compared to the current randomized stacking strategy in the container terminal.