Circular economy strategies at the manufacturing system scheduling level: the impacts on Makespan

The use of end-of-life and end-of-use products to recover parts and raw materials can mitigate the severity of the increasing price of raw materials, the disruption of global supply chains for critical raw materials (e.g., chips and rare earth elements), and reduce the environmental impacts. Furthermore, circular economy strategies can improve scheduling by shortening the completion times of the components. This paper investigates the effects of implementing circular economy strategies (repair, reuse, and re-manufacturing) at the scheduling level in a manufacturing system involving disassembly, re-manufacturing, and assembly operations. A set of eight priority rules modify the job priority and the strategy implementation. The results show that including circular economy strategies through disassembly can reduce the makespan, but scheduling is pivotal to managing the frequent changes in the quality of end-of-life products and their volumes and the current production order mix.