A practical module-based simulation model for transshipment-inventory systems

A method of modeling trans-shipment-inventory systems is proposed in an attempt to describe systems where many kinds of items are ordered to be transported, stored and delivered to the customers. The system consists of a number of supply, trans-shipment and demand nodes. However, the problem considered in this study is totally different from the traditional trans-shipment problem in terms of linear programming. Firstly, any number of different kinds of items can be treated for analysis. Secondly, any size of transportation trucks can be specified to transport items for any number of the two-node combinations. In other words, the capacity of the transportation truck is to be specified in building a simulation model. In addition, any number of supply, transshipment and demand nodes can be specified in a simulation model. Thirdly, the order by a demand node is made toward the associated trans-shipment node, based on the inventory policy at the demand node, and the so-called the "pull system" is adopted in the demand-supply environment. An efficient module-based modeling method is proposed to generate simulation models for the above-mentioned trans-shipment-inventory systems. The proposed method is applied to the actual system. It is found that the time to build simulation models could be drastically reduced. Furthermore, the proposed method is found to be both practical and powerful.