A Worker-Centric Order Release Method Based on Workload Control: An Assessment by Simulation

This study presents a novel paradigm of production planning and control by introducing a worker-centric workload control order release approach, which is particularly suitable for the manufacturing shops involving robots and workers, such as the human-machine collaborative production system. Specifically, a production order in the real-life production process may consist of multiple operations. Some of these operations are exclusively performed by machines and others necessitating collaboration between workers and machines. This will make it more difficult for managers to balance the workload on the shop floor, even deteriorating the available capacity of workers and machines. Therefore, this study first classifies the production orders into two kinds of tasks (i.e., independent tasks and collaborative tasks) based on their processing attributes before holding them in a pre-shop pool. Subsequently, we give priority to releasing the workload of collaborative tasks (i.e., triggered by the workers) and subsequently release independent tasks (i.e., triggered by the independent machines) to balance the workload across machines at the order release stage. The experimental results demonstrate that prioritizing worker workload balance can significantly improve the shop performance in terms of throughput time and tardiness time. Furthermore, we observe that prioritizing workers’ workload also mitigates tardiness typically associated with high load periods when expediting the processing of urgent orders. In other words, prioritizing workers’ workload to some extent diminishes the disparity between high load and low load periods due to this is conducive to avoiding premature idle or overload of small capacity resources, therefore leading to a more balanced workload on the manufacturing shops.