What makes order picking so physically demanding?-Ergonomic evidence from a large-scale lab experiment using subjective metrics

Order picking is a critical and resource-intensive process within warehouse operations. Many warehouses still heavily rely on human operators for picking orders. However, human order pickers have become a scarce resource, partly due to the physically demanding nature of the order picking process. If warehouses want to remain competitive, they should properly account for physical worker well-being. Unlike earlier research which mainly focused on objective metrics, this paper investigates the factors that contribute to subjective physical exertion. Specifically, we conduct a large-scale lab experiment (N=164) and derive the perceived ergonomic exertion with the Borg CR-10 scale. Results show the significance of shelf height, product weight, and product quantity on ergonomics. On the other hand, elements such as picker sociodemographics, the prevailing incentive system, or the degree of autonomy are less suitable to predict perceived physical exertion; they might be more relevant to influence psychosocial well-being though. Our study shows thus that physical worker well-being is primarily determined by the attributes of the order to be picked. Based on our results we propose several suggestions for future research and ergonomic OP system design.