During the Industrial Revolution and particularly at the beginning of the Second World War, mathematicians and those involved in the industry became interested in the optimization models. The application of these model was specially developed in industry and services sector after the Second World War. Based on this, designing of the mathematical model for the transportation network of Islamic Republic of Iran’s Post Corporation, which is practically complicated as a result of the multiplicity of communication paths and the variation of transportation systems and vehicles as well as mail items, will be studied according to a multi-level model.
First the transportation system’s data is loaded into the post corporation’s system of transportation data. After estimating the Function Utility of the system, the shortest time and path as well as the vehicle carrying the intended mail item between the two post offices (i & j) will be identified. Finally, the consignments will be transported through the selected paths and based on their weights.
Therefore, besides reviewing the related literature, the history of transportation

systems as well as postal transportation systems will be discussed. Finally, based on the methodology, the findings and proposals will be presented through a multi-level mathematical model.