An optimization model for management of empty containers in distribution network of a logistics company under uncertainty
Subject Areas : Mathematical OptimizationAhmad Hosseini 1 , Tobias Sahlin 2
1 - Department of Computing Science, Umeå University, 901 87, Umeå, Sweden
2 - Department of Mathematics and Mathematical Statistics, Umeå University, 901 87, Umeå, Sweden
Keywords: Operations research . Uncertain programming . Logistics. Intermodal transport . Repositioning,
Abstract :
In transportation via containers, unbalanced movement of loaded containers forces shipping companies to reposition empty containers. This study addresses the problem ofempty container repositioning(ECR) in the distribution network of a European logistics company, where some restrictions impose decision making in an uncertain environment. The problem involves dispatching empty containers of multiple types and various conditions (dirty and clean) to meet the on-time delivery requirements and repositioning the other containers to terminals, depots, and cleaning stations. A multi-period optimization model is developed to help make tactical decisions under uncertainty and data shortage for flow management of empty containers over a predetermined planning horizon. Employing theoperational lawofuncertainty programming, a new auxiliarychance-constrained programmingis established for the ECR problem, and we prove the existence of an equivalence relation between the ECR plans in the uncertain network and those in an auxiliary deterministic network. Exploiting this new problem, we give the uncertainty distribution of the overall optimal ECR operational cost. The computational experiments show that the model generates good-quality repositioning plans and demonstrate that cost and modality improvement can be achieved in the network.