Modelling Wholesale Company’s Supply Chain Using System Dynamics

Abstract

Research is based on wholesale and distribution operations of real-life case company, and in this setting, the most critical part of company’s supply chain is the inventory replenishment to warehouse (Distribution Center) as well as fulfilling and delivering customers’ orders. Different Economic Order Quantity (EOQ)-based models have been considered (Reorder Point, Reorder Point with pipeline on order inventory, and “pulse train”). Simulation system evaluates annual total logistics costs. Results show that in an environment, where local warehouse inventory levels are rather high and replenishment order quantity is rather small, it is important have frequent shipments divided in suitable intervals. In simulation model, this could be done e.g. with the use of “pulse train” function or incorporating pipeline on order inventory in order decision. The research findings are valid for a small-scale supply chain servicing small and geographically limited markets with clients assuming high customer service levels (e.g. 24-hours lead time). For bigger markets, the cross-docking based supply chain models are worth considering in simulations.

Keywords

• logistics costs
• inventory replenishment models
• supply chain simulation
• system dynamics