Ship routing and scheduling with inventory and stowage constraints

Abstract

We present a real planning problem where cement is transported by a fleet of ships from several production factories to many consumption silos along the Norwegian coast. The planners are responsible for both the ship routing and the inventory management at all production and consumption facilities. There exist several types of cement and the various types have to be allocated in separate cargo holds onboard the ships. The utilization of a ship’s cargo carrying capacity depend on the stowage. We have developed a heuristic to solve this real complex inventory ship routing and scheduling problem with stowage constraints. Computational results from the real case study will be presented. Various objective functions have also been tested, and it seems that using cost-per-ton gives best solutions for the real problem.