Optimization of Container Ship Stowage Plans

The container ship stowage planning problem was introduced to the research group by the container transport company Euroports. The goal of this so called Master Bay Plan Problem (MBPP) is to minimize the total stowage time to transport a given set of cargo. Although the MBPP is a general definition of the problem, it differs in two aspects. First, the MBPP takes into account an individual loading time for each container and aims to minimize the total loading time. Second, containers are located into fixed slots in the cargo space. Our approach aims to minimize the total container operations or shifts consisting of unloading and reloading operations caused by blocking containers. In the first stage an alternative model is developed: the Sliced Bar Packing Model (SBPM). Bars represent containers from the pick up till the destination terminal. These bars can be cut into multiple parts and are packed in a given space, while the total number of cuts should be minimized. In the second stage, a heuristic solves stowage problems represented by the SBPM. The performance of the SBPM heuristic is compared to the Suspensory Heuristic (SH) introduced by Avriel et al. Results show that the SBPM outperforms the SH. In addition, while the SH is limited to a homogeneous set of containers and cannot take into account stability constraints, the SBPM accommodates these needs.status: publishe