Shipping Liner Company Stowage Plans: An Optimization Approach

The problem of determining the stowage plan for each port included in the circular route of a containership is the planning problem daily faced by the shipping line coordinator (SC). The SC has to determine how to stow in each port a given set of containers into bay locations, either on the deck or in the hold, in order to satisfy some structural and operational constraints, all the transport demand and minimize the ship berthing time. The time spent by the ship at the ports is minimized when the SC defines a stowage plan that avoids re-handles, balances the workload of the cranes working in parallel at each port and requires to open and close hatches the least possible when moving containers in the holds. We propose a new MIP formulation, and a MIP heuristics for finding stowage plans for containerships up to 18000 TEUs. Moreover, the new formulation includes new and more accurate stability conditions.