Solving the Robust Container Pre-Marshalling Problem

Tierney K, Voß S. Solving the Robust Container Pre-Marshalling Problem. In: Paias A, Ruthmair M, Voß S, eds. Computational Logistics: 7th International Conference, ICCL 2016, Lisbon, Portugal, September 7-9, 2016, Proceedings. Lecture Notes in Computer Science. Vol 9855. Cham: Springer International Publishing; 2016: 131-145.Container terminals across the world sort the containers in the stacks in their yard in a process called pre-marshalling to ensure their efficient retrieval for onward transport. The container pre-marshalling problem (CPMP) has mainly been considered from a deterministic perspective, with containers being assigned an exact exit time from the yard. However, exact exit times are rarely known, and most containers can at best be assigned a time interval in which they are expected to leave. We propose a method for solving the robust CPMP (RCPMP) to optimality that computes a relaxation of the robust problem and leverages this within a solution procedure for the deterministic CPMP. Our method outperforms the state-of-the-art approach on a dataset of 900 RCPMP instances, finding solutions in many cases in under a second