Optimizing green supply chain for perishable products considering nano-silver packaging under uncertain demand

Traditional supply chain designer has not considered environmental factors during designing a food supply chain. However, the protection of the environment is one of the most important criteria that should be evaluated according to the world environmental protection regulations. Perishable items are one of the most sensitive products in the food supply chain which have limited shelf life criteria besides other complexity of the typical supply chain. Wastage in this supply chain is more than in other food industries. Wastage in final products means waste in natural sources, fertilizers, etc. Therefore, this wastage has a significant influence on the greenness of the chain. Hence, decreasing the waste of perishable products has a significant influence on total profit and environmental criteria. Two main solutions exist to decrease wastes: (1) improve packaging and (2) optimize planning. To improve packaging an efficient biodegradable nano-silver packaging method has been imported into a mathematical model. To optimize planning, a multi-objective mix-integer mathematical model is developed to maximize total profit and minimize total carbon dioxide emissions from transportation. Moreover, to deal with uncertainty, a set-based robust optimization has been applied. The mathematical model optimizes technical decisions of the supply chain in a three-echelon chain. To show the efficiency and applicability of the proposed method, a case study for protein products has been implemented. The results show that it is possible to reduce carbon emissions without increasing the total cost. Furthermore, a sensitivity analysis on nano-silver packaging and its influence on profit and the environment has been prepared that shows using nano-silver have a positive influence on profit and greenness of the chain.