Design of a Pharmaceutical supply chain under uncertainty and reverse logistic

The design of supply chain networks has always been important from the point of view of artisan and decision makers. The optimization of supply chain network becomes more important with the advent of the supply chain of perishable goods, especially perishable drugs, because inventory management is one of the vital decisions in this supply chain to prevent spoilage and shortage of drugs. In this paper, a new bi-objective mixed integer nonlinear programming with forward and reverse logistic simultaneously is represented to manage the production of perishable drugs as well as their distribution. This multi-echelon supply chain includes suppliers, potential production centers, potential distribution centers, potential recycling centers, potential disposal centers and recycled product markets along with multi-period and multi-product assumptions. Considering discounts on purchasing from suppliers, warehousing in distribution centers, uncertainty in demand and the use of alternative goods to avoid shortages in order to meet the social criteria are among the contribution of this study. To solve the proposed bi-objective nonlinear model including minimizing the total costs of the chain and minimizing the maximum shortage, the linearization technique and transmission bi-objective model to single-objective model were used under the fuzzy uncertainty conditions. After validating the proposed model, 12 instances were randomly generated in different dimensions to measure the efficiency of the model and solved in GAMS software. The efficiency of the proposed model is shown in the obtained Pareto set for a particular instance. The results of sensitivity analysis show that with increasing the percentage of recycled products, the first objective function has increased and the second objective function has not change. This paper can help the managers benefit from reverse logistics, recycling of perishable products and paying attention to social criteria in order to gain a competitive privilege throughout the drug supply.