Single order versus batch order-picking and Warehousing 5.0: Analyzing human factor

Current market trends, such as the adoption of omnichannel strategies and rising customer expectations, have introduced challenges in warehouse operations. While automation has improved efficiency, the human factor remains critical, particularly in order-picking, which demands physical and cognitive effort. In line with the Warehouse 5.0 paradigm, this study combines performance and worker perspectives, investigating how picking policies shape operator cognitive load and operational outcomes. An experimental methodology was adopted, involving a laboratory simulation of picking tasks under two policies, i.e. single order and batch order-picking. Cognitive load was assessed through a multidimensional approach combining physiological measures (EEG-based attention level, arousal level) and self-reported perceived mental demand. Results show that batch strategy, compared to single order-picking, presents productivity advantages (19.5%), while increasing perceived mental demand (26.4%), level of attention (10.9% in males), and error rate (105.0%), with all effects statistically significant. The mediating role of human factor (specifically, cognitive dimension) and the moderating role of individual worker characteristics (e.g. gender) in the relationship between picking policies and performances are highlighted. The quantitative evidence obtained from controlled experiments on how the interplay of picking policy and cognitive load affects individual and system performance offers actionable insights to advance human-centric decision-making processes.