Impacts of Capacity Redundancy and Process Flexibility on Risk Mitigation in E-Waste Recycling Supply Chain Management

Recently Waste Electrical and Electronic equipment (WEEE) has become urgent environmental issues around the world. Generally, the e-waste recycling reverse supply chain (RSC) is featured as higher uncertainties and complicated network structures, making the operation more difficult. To meet the challenge of uncertainty, this research investigates the values of capacity redundancy and process flexibility in e-waste recycling reverse supply chain management. Although the two strategies have been extensively studied in forward supply chain (FSC), the study on impact of hybrid uncertainty mitigation strategy in RSC is rare. Thus, we study the coupling effect of capacity redundancy and process flexibility through the design of two hybrid strategies. The e-waste recycling process is formulated as a two-stage stochastic programming model. Uncertainties of both wastes returns and resource yields are considered and handled by a distributionally robust optimization method, then a computational tractable second-order cone programming model is obtained using an adaptive robust reformulation and solved effectively by a proposed Outer Approximation (OA) algorithm. With numerical experiments based on real data implemented, our research finds conflict situations of using capacity redundancy and process flexibility strategies together, gives guidelines for the use of hybrid strategies in reverse supply chain and contributes to improve the understanding of redundancy and process flexibility strategies as well as their coupling effect