A human-centric order release method based on workload control in high-variety make-to-order shops towards Industry 5.0

Industry 5.0 emphasizes a human-centric concept, aiming to construct highly intelligent, sustainable, and resilient manufacturing systems. While a large body of literature has explored its concepts, architectures, enabling technologies, and practical applications, literature specifically focused on production planning and control solutions in industry 5.0 shops are scarce. Recent literature indicates that the well-being and skills of human workers significantly impact shop performance due to their highly variable activities and behaviors. Workload control has been recognized as a simple yet effective solution to mitigate the effects of high variability both human and machine - through a three-layer filter for high-variety make-to-order shops, offering potential for Industry 5.0. However, the existing workload control concept has two significant limitations. First, it primarily focuses on the workload of machines while ignoring the potential impacts of humans, and; Second, this concept relied on the fixed processing times and lack flexibility to cope with changes in human subjective behaviors. In response, this study first presents a human-centric order release method based on workload control, enhancing its adaptability by considering uncertain human processing times. Furthermore, we introduce five shop floor priority dispatching rules to further investigate the potential impacts of additional factors on our proposed method. Simulation results show that the human-centric method outperforms the traditional machinecentric method, particularly in pure job shops. Meanwhile, when combining the human-centric order release method with the shop floor dispatching rules, the load-oriented dispatching rules significantly improve the shop's performance in terms of throughput time, while the time-oriented dispatching rules increase order delivery performance. Counterintuitively, integrating human-centric concept into the shop floor dispatching stage is noteworthy, i.e. human-centric shop floor dispatching rule. It does not enhance shop performance compared to the original dispatching rules, but rather deteriorates the performance of order release on most measures. The findings of this study have important implications for both research and practice in Industry 5.0.