Greenhouse Gas Emissions Optimization for Distribution and Vehicle Routing Problem in a Poultry Meat Supply Chain in Two Phases: a Case Study in Iran

Sustainable transportation has become a central issue for scholars around the world. It is now well established that the transportation sector is one of the few industrial segments escalating greenhouse gas emissions. On the other hand, Tehran as one of the most populous cities in the world has been constantly confronting environmental challenges, particularly the motor vehicles’ pollution. Therefore, the objectives of this study were to (1) determine the optimal capacity of slaughterhouses, (2) identify the best routes for transporting, and (3) reduce the number of vehicles used, transportation costs, and greenhouse gas emission costs. The model is presented in two phases that solved using the general algebraic modeling system (GAMS) software for data set of the real instance. The results of phase 1 indicated that using the designed transportation model might reduce transportation costs by 0.3 and 9.8%. In addition, as slaughterhouse capacity increased, the average cost per period decreased by 8.5%. The results of phase 2 demonstrated that using the designed transportation model might reduce costs of transportation for 3 days by 29.56, 27.91, and 32.58%, respectively. In addition, the costs of greenhouse gas emissions would decrease by 17.29, 22.82, and 23.08%, respectively.