Multi-objective sustainable production planning for a hybrid multi-stage manufacturing-remanufacturing system with grade-based classification of recovered and remanufactured products

In this paper, we address the problem of multi-objective production planning in a hybrid manufacturing and remanufacturing system (HMRS), introducing several significant contributions. First, we propose a new formulation of the problem that extends the existing literature by introducing a multi-objective model. This model aims to minimize both total costs and $$CO_2$$ C O 2 emissions within a hybrid system composed of various machines in charge of producing new and remanufactured products of different qualities. To efficiently solve this complex problem, we present an innovative approach that integrates several techniques, including NSGA-II, the entropy weight method and the TOPSIS technique. Our research focuses on the economic and environmental aspects of the remanufacturing process, seeking to determine the optimal manufacturing and remanufacturing plan. This plan aims to meet demand for new products and maximize satisfaction for remanufactured products of different qualities, while minimizing the total economic costs and $$CO_2$$ C O 2 emissions incurred during the various manufacturing and remanufacturing stages, including set-up, production, inventory and disposal. To address the multi-objective nature of this problem, we develop a mathematical model and introduce an approach based on the non-dominated genetic sorting algorithm (NSGA-II). To help decision-making, we use the technique of performance ranking by similarity to the ideal solution (TOPSIS) in combination with the entropy weight method (EWM) to objectively obtain the optimal compromise solution from the Pareto front provided by NSGA-II. Finally, we conduct computational experiments to assess the environmental impact of carbon emissions associated with new, remanufactured and discarded products over a finite production horizon. We illustrate the adaptability of the proposed approach by applying it to two distinct remanufacturing strategies: one where remanufacturing is used to reduce waste, and one where demand for remanufactured products is critical, with a penalty cost associated with any shortfall in demand.