Heterogeneous Tramp Ship Scheduling and Speed Optimization with Fuzzy Time Window

In order to improve the cargo owner’s satisfaction and obtain better economic benefits for shipping companies, the ship deployment along routes and speed optimization of tramp ships are studied, considering the influencing factors of ship scheduling with the configuration and speed of self-owned ships and chartered ships. A goal is developed by minimizing sailing cost, fuel, and waiting cost at ports, penalty cost for late arrival at ports, time cost, and voyage ship chartering cost by applying fuzzy time window to characterize the cargo owner’s satisfaction. The model of scheduling and speed optimization with fuzzy time window for heterogeneous tramp ships is established. A variable neighborhood genetic simulated annealing (VNGSA) algorithm is presented to solve the problem. First, the ship type is matched with the cargo. Then the route is generated according to the time constraint. Finally, the neighborhood search strategy is adopted to improve the solution quality. Computational results indicate that integrated planning for ship scheduling and speed can reduce sailing cost; considering time requirement of cargo owners can increase their satisfaction. This paper can enrich tramp ship routing and speed optimization problems and provide a theoretical tool for shipping companies to make related decisions.