sustainable tire closed-loop supply chain design under uncertain return and demand

Each year, millions of tires that have reached their end of life are either buried or burned, both of which harm the environment through polluting the air and groundwater. companies need to consider their social responsibility, including employment and regional development, and the environmental impact of their activities when making strategic and operational decisions. this study addresses the closed-loop supply chain (clsc) design problem with regard to the dimensions of sustainability. the options of retreading, recycling, and energy recovery, along with the use of green technologies are considered to minimize environmental impacts. the proposed decision approach uses life cycle assessment (lca)-based social indicators to model its social impacts, along with the use of eco-indicator 99 as a method of assessing environmental impacts. the developed mathematical model turns out to be a multi-objective, mixed-integer linear programming (momilp) model that considers population density and unemployment rate in the social dimension. the model is solved using the lp-metric method and cplex solver. a scenario-based approach is used to address the uncertainty in demand and the return of worn-out tires. the results show to which extent considering social sustainability, along with uncertainties in demand and return, impacts location and technology selection decisions in the tire clsc design problem. besides, the economic and environmental dimensions are also affected when considering social indicators, because of relocation and changes in the distances between the various supply chain centers, which in turn results in changes in costs and pollutant emissions.