Design of a multi-echelon global supply chain network with MicrosoftRTM Excel premium solver platform

I designed a global supply chain distribution model of one single product, with the objective of minimizing the costs of transportation, handling materials, duties and tariffs, production, and fixed infrastructure. The distribution network has a combination of manufacturing facilities (fixed and to-be-determined), warehouses (to-be-determined), distribution centers (to-be-determined), and customer zones at fixed locations. This network design is similar to the mathematical mixed-integer linear model from Tsiakis, Shah and Pantelides (2001). This model has been implemented in Microsoft Excel, using the Standard Simplex method from Frontline, Inc. This model optimizes the number of facilities worldwide (multi-echelon) along with the flow of materials per transportation node to meet demand of several regions of the world. Any combination of nodes is possible, although the production rate at each manufacturing facility must be able to provide all materials required at each region - no extension is allowed. A supplementary mixed-integer model is provided to address country's economic freedom when selecting global manufacturing sites.