61 / 2024-04-18 10:00:18

Optimal Loading and Unloading Dock Model for Seaport Terminals

Port berth; Port congestion; Delayed ship; Mixed-integer programming; Goal programming

Complex and changing international relations and their forms of economic development have led to the increase of congestion problems and idling in seaports. This has not only caused growth in cargo throughout some seaports, but also triggered a series of chain reactions such as sharp increases in raw material prices and supply delays. To solve congestion problems, this paper proposes flexible scheduling models. It considers diverse loading and unloading demands, along with the potential for certain ships to be delayed in their arrival. It achieves several optimization objectives including the shortest total waiting time considering ship types, ensuring an equitable distribution of tasks across berths, early completion of the scheduling task, adhering as closely as possible to the anticipated docking times for each ship, and the shortest waiting time for delayed ships. Through theoretical derivation, the real demand of ships for both unloading and loading of cargo is integrated into the joint docking time slot and duration. Our models optimize the overall scheduling scheme of ships. Simulation results driven by actual real life data demonstrate that the model is capable of effectively solving the problem of loading and unloading congestion at terminals. It can also be extended to suit the docking demands in special contexts. At the same time, this paper further confirms that the model has a generalized application value in complex multi-window and multi-time window queuing problems.