Zero waste strategy for green supply chain management with minimization of energy consumption

Conservation of natural resources, reduction of waste, and minimization of energy consumption is now the primary focus of green supply chain management. In order to address the objectives of green supply chain management, this paper suggests a supply chain model to practically eliminate waste from the system while consuming a minimum amount of energy. The target of “zero waste” is achieved by structuring three layers of supply chains, viz., primary supply chain, secondary supply chain, and reverse supply chain. The primary product deteriorates at a specific rate, which creates a substantial amount of waste. The waste disposed of by consumers is categorically segregated into “main product waste” and “packaging waste” at a collection center. The main product waste is converted into a secondary product through a secondary supply chain and the packaging waste is recycled into the same product through a reverse supply chain. The three layers of supply chain are connected at the collection center, which maintains inventory of the collected waste and provides material to the secondary supply chain and the reverse supply chain. In this paper, we propose a model for the centralized supply chain system (i.e., the three layers of supply chain making decisions jointly) by defining a nonlinear mathematical model for minimizing total cost. In particular, the minimum value of the cost is obtained by searching for the optimal period in the planning horizon through an analytical optimization technique. In addition, we minimize the energy consumed for producing the primary and secondary products and recycling the packaging material. Robustness of the model is verified through numerical experiments and sensitivity analysis. The proposed model achieves 98.4% efficiency of waste removal, which is demonstrated through the results of numerical experiments. The obtained optimal length for the planning horizon provides the optimal production time and minimizes the consumption of energy.