Sustainable closed-loop supply chain network design and operations planning considering human resource employment and training

Modeling and optimal solving of supply chain management problems lead to efficient decision making in strategic planning and supply chain operations, resulting in a competitive advantage. Today, with the planning of a sustainable supply chain, in addition to achieving economic goals, it is possible to meet social and environmental objectives and considerations. This research deal with sustainable closed-loop supply chain network design and operations planning problem in which is human resource employment and training are considered. First, a three-objective optimization model is developed in which the supply chain network is designed and strategic variables (such as location and capacity determination, technology selection, skilled or semi-skilled employment and training, and etc.) are obtained. Then, a multi-period model is proposed supply chain operations planning in which the amount of production, inventory, shortage, temporary recruitment of manpower, etc. in each period are determined. In the proposed strategic model, a trade-off between the objectives of minimizing the cost of the supply chain (economic), maximizing employment (social), and minimizing environmental impacts is done by augmented epsilon constraint method. Also, Benders decomposition algorithm is used to solve large-scaled instances. In the final section of the research, some numerical studies are presented to provide numerical results, managerial insights and evaluating the performance of the proposed model and solution approaches.