Supply Chain Redesign with Routing Consideration

Due to the changes in the condition of every supply chain it is possible that the first optimal network design become inefficient .These changes can be caused by different reasons like changes in amounts or location of demands, changes in suppliers, costs, taxes, government regulations etc. So, it is necessary to redesign networks to obtain their new optimal configuration for adopting to new conditions. This paper proposes a new mathematical model for a multi-product supply chain network redesign problem. Since one of the main problems of real-world cases deals with is transportation, routing constraints in every echelon (plant to warehouse and warehouse to customer) are considered in the proposed model. In addition, a capacitated and heterogeneous fleet of transportation in a split delivery system is used to deliver demands of the first echelon to the warehouses and demands of the second echelon to customers. On the other hand, due to the production capacity of the manufacturers, some portions of demands is satisfied by outsourcing. The outsourced products are moved to the warehouses directly. The proposed model is validated through an illustrative example by some strong servers in a website which is used to solve the mathematical modeling problems. Then, some sensitive analysis are performed in order to investigate the effects of some key parameters on the optimal cost and figure of the network. Finally, we can reach the conclusion of need to consider the transportation and routing costs, and it is necessary to account outsourcing and some other costs and benefits in our redesign problems as well.