Shadi Nouhi Tehrani - School of Industrial Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
Ali Bozorgi-Amiri - School of Industrial Engineering, College of Engineering, University of Tehran, Tehran, Iran

The combination of transportation costs is very important in supplier decisions. This article discusses supplier selection and assignment of orders in a supply chain logistics system. This article is intended to a multi-period vehicle routing problem with considering the assignment of orders by multiple vehicles from multi suppliers, taking into account storage and transportation, in order to limit planning horizon for each orders. We provide an integer linear programming model for determining the optimal policy in the supply chain and the allocation of orders to the suppliers, which is also include the supply of goods between suppliers. The allocated of order with each factory is assumed to be time varying and deterministic. We proposed a new mathematical model, this model is represented by a mixed-integer linear program the objective function to minimization operational costs. Finally, we solved the model on the GAMS software and to show the applicability of the proposed new model.

logistic, vehicle routing problem, order allocation, Mixed-integer linear programming