An Improved Storage-Space Selection Model and Algorithm for Outbound Shipping Containers: Considering the Synchronous Operation of Multiple Gantry Cranes in Port Terminals Worldwide

Enhancing operation efficiency and strengthening core competence of storage yard are vital to exist and succeed for container ports worldwide. Aiming at improving container terminals' operational efficiency, this paper researches selecting locations for outbound containers and optimizing the relocation paths during retrieval operations. The outbound containers' storage-space selection problems (OCSSSP) can be concerned with emptying all the containers stacked in one block where every outbound container is given a fixed extractive sequence with the fewest number of relocations. The OCSSSP is a Non-Deterministic Polynomial Hard Problem. To increase the practical guiding significance of research conclusion, this paper further improves the model from synchronous operations of gantry cranes. The research content extends from one single piece of equipment to multiple pieces of equipment and conducts an in-depth study on the operation of a single piece of equipment, the independent operation of multiple pieces of equipment, and the collaborative operation of multiple pieces of equipment. Numerical experiment results show that the effect of the collaborative operation between different gantry cranes is best, and the container relocation number is least. Therefore, delimiting the joint operation areas between different gantry cranes makes the operation efficiency higher and the resources more reasonably utilized. This paper is consistent with the frontier to logistics development and satisfies the needs of developing technology and solving management problems in coastal container ports worldwide; therefore, this research has meritorious theoretical perceptiveness and considerable economic practicability.