Quality inspection and condition-based preventive maintenance in a closed-loop multi-stage manufacturing system

This research presents the development of a Serial-Closed-Loop-Multi-Stage Manufacturing System from a circular economy perspective. The system integrates a production line where five specialized machines operate across both forward and reverse remanufacturing processes. However, due to varying deterioration levels, these machines cannot consistently produce defect-free items, resulting in increased scrap and customer penalty costs. To address this challenge, we propose a mixed-integer linear programming (MILP) model that optimally allocates quality inspection stations and schedules for preventive maintenance across multiple working shifts. The objective is to minimize total production costs, including quality control, maintenance and customer penalties. The model’s effectiveness is validated through numerical experiments under three distinct machine deterioration scenarios, demonstrating its potential to enhance efficiency and sustainability in modern manufacturing systems.