Scheduling tank container movements for chemical logistics

Abstract

Effective logistics is the key to improving supply chain performance. Tank containers are attractive from the viewpoints of safety, cost, and environment, and are widely used for transporting fluid chemicals. Minimizing the logistics costs arising from the container flow imbalances across the globe and container cleaning is a major issue that chemical companies and affiliated third-party logistics firms face routinely. In contrast to dry containers, this important problem of managing tank containers in global chemical logistics has received no attention. An innovative, event-based, "pull" approach is presented for the minimum-cost or the maximum-profit scheduling of the transport and cleaning of multiproduct tank containers (loaded and empty) given a set of projected shipment orders. A novel linear programming formulation is developed and illustrated through examples that successfully solves large, industrially relevant problems with key practical considerations such as alternate ship schedules, delivery time windows, and intermodal transport routes. © 2004 American Institute of Chemical Engineers.