Metaheuristic algorithm for ship routing and scheduling problems with time window

This paper describes a Tabu Search (TS) heuristic for a Ship Routing and Scheduling Problem (SRSP). The method was developed to address the problem of loading cargos for many customers using heterogeneous ships. Constraints include delivery time windows imposed by customers, the time horizon by which all deliveries must be made, and ship capacities. The proposed algorithm aims to minimize the overall cost of shipping operation without any violations. The TS algorithm is compared with a similar method that uses the Set Partitioning Problem (SPP) in terms of solution quality and computational time. The results of a computational investigation are presented. Solution quality and execution time are explored with respect to problem size and parameters controlling the TS such neighborhood size. It is found that while the SPP method solves small-scale problems efficiently, treating large-scale problems with this method becomes complicated due to computational problems; however, the TS method can overcome this challenge. Furthermore, TS consistently returns near-optimal solution within a reasonable time.