A method of ship scheduling and inventory management problem for reducing demurrage and freight

摘要

This paper deals with ship scheduling and inventory management by considering both shipping costs and demurrage costs with hourly precision. First, the formulation of an optimization model of the problem is described. Then, a hierarchical scheduling approach is newly introduced, which enables us to get a schedule close to the optimal within reasonable computational time. Moreover, through some computational experiments with some examples of practical size, the effectiveness of the proposed approach is examined, where the results obtained by using the proposed approach are compared with those by directly optimization method based on the mathematical programming approach and by heuristic method based on the rule-based approach. Finally, the effectiveness and the potential of the proposed approach with respect to the balance between the quality of the obtained schedule and the time required for computation are confirmed.