Modeling a Multi-Objective Green Inventory-Routing Problem with Transshipment Option

Overview & Synopsis

This paper addresses a multi-period inventory routing problem (IRP) where capacitated vehicles distribute products from multiple suppliers to one retailer to meet the given demand of products. The demand associated with retailer is assumed to be time varying and deterministic. Greenhouse gases emission is a major concern globally since they are key players in global warming. Routing decisions can help in the reduction of Greenhouse gases emissions if these emissions are taken into account by the decision makers. Also, the transshipment option as one of the main topics of this paper is considered in the proposed model. The transshipment option is one of the most recent things that can be considered today in supply chain management. This option makes the vehicle meet the required product of a node directly from the product supplier's node or from a node previously stored in a product temporarily. As a result, it reduces greenhouse gases and costs by reducing the distance traveled. The proposed model is a mixed-integer linear program that coded and solved in GAMS. We provide a numerical study showing the applicability of the model.