Circular economy at scheduling level: influencing factors and impacts on system performance

In manufacturing systems, Circular economy (CE) strategies to recover returned end-of-life prod-ucts can reduce raw material purchasing costs and lead times while improving environmental performance. However, CE strategies may undermine production planning, control, and inventory management activities, and there is a lack of scientific evidence about the impact on work-in-progress (WIP) and overall performance. This paper uses Discrete Event Simulation to analyse the factors influencing the exploitation of returned products under different CE strategies and priority rules. The experiments investigate the impacts on makespan, virgin raw material consumptions, and WIP at the scheduling level in a realistic production and assembly system where production is coupled with disassembly, repairing, remanufacturing, and reusing. The results highlight the importance of production control strategies in limiting the negative impacts of CE strategies on WIP, makespan,and materials consumption. Moreover, frequent rescheduling is required due to the high variability affecting the systems implementing CE strategies.