Optimization of closed-loop supply chains with a waste management and recycling approach: Examining the effects of capacity, facility location, and uncertainty management in responding to variable demand

The closed-loop supply chain, as an innovative model in supply chain management, provides a sustainable solution for managing resources and waste with a focus on reducing environmental impacts and enhancing resource efficiency. In recent years, the increasing environmental pollution and its irreversible constraints have highlighted the need for sustainable solutions in the supply chains of various industries. This study utilizes robust optimization to design and optimize closed-loop supply chain processes under uncertainty, aiming to reduce waste production, natural resource consumption, and pollutant emissions. The proposed model considers the closed-loop supply chain as a multi-dimensional system that includes production, distribution, collection, and recycling of goods. The optimization of facility location and capacity for distribution, collection, and recycling centers is also part of this model, which helps reduce costs and improve supply chain efficiency. The results of the analyses show that robust optimization enhances the model's performance under uncertain conditions and leads to optimal and sustainable decision-making in the supply chain. Sensitivity analysis revealed that specific vital parameters significantly affect the objective function, and precise management of these parameters can play a crucial role in the success of optimization strategies. Ultimately, this research demonstrates that the closed-loop supply chain, by reducing dependence on natural resources and controlling pollutants, acts as a practical approach to environmental sustainability, balancing economic needs with environmental responsibilities.