Using Linear Planning for Optimal Distribution of Asphalt from Plants to Multiple Projects (Case Study: Projects of Khuzestan Province)

Road pavement deteriorate continually due to numerous factors therefore beneficiary organizations define road restoration and refinement projects annually. Implementation of these projects requires supplying asphalt from available asphalt factories. A desired asphalt factory needed by each project should not only be near to the project's site but also have free production capacity proportional to the project's demand. Large distance between the factory and the project site results in increased transportation costs and, as a result, increased implementation costs and lack of free production capacity leads to delayed delivery of asphalt and, consequently, a delay in project implementation. A centralized and integrated production and distribution planning system for various factories can provide the most optimal balance between demand and production capacity of various supplying factories. This study presents an "integrated asphalt production and distribution planning" model (BITA) for asphalt factories which is called BITA Optimization Model. In this model, asphalt amount required by each project (Dai), production capacity of each asphalt factory (Capj), transportation distance between factory and project site (dtij), transportation costs in different paths (Ctij) and asphalt price of each factory for each project (Cpij) are delivered to the model as input data. Then, the model is coded in GAMS Optimization software and the variable "asphalt amount assigned by each factory to each project in each period" (Xijt) is computed as the model output using Solver CPLEX. To explain how the proposed model can be used, an applied example of integrating "production and distribution planning" between 20 asphalt factories and 15 sites requiring asphalt in Khuzestan Province during one year will be presented at the end of this article.