A study on the control of an automatic picking system (APS) in a warehouse

摘要

Purpose - This paper aims to explore methods of defining ejecting zones (EZs) used in automatic picking systems (APSs), particularly in A-frame APSs. An A-frame APS automatically ejects products onto a conveyor, which then brings the products to their destination. EZs are moving zones on a conveyor, and each EZ corresponds to one picking order. Products are ejected as a zone passes channels in which the products are stored. Design/methodology/approach - First, three EZ types are defined, and their operations are explained. Second, picking orders are analyzed and categorized by considering the structure and the picking mechanism of an A-frame APS. In addition, picking-order instances reflecting actual data are randomly generated according to each category. Finally, the performance of the EZs is evaluated using the picking-order instances and computer simulations. Findings - The results from the computer simulations suggest the EZ types suitable for use with various picking order types considering order fulfilment speed and energy usage. Research limitations/implications - In this paper, the authors only adopt a triangular distribution which is considered most practical distribution in the industry. Practical implications - It is believed that these results can provide managers and operators with useful guides to facilitate the effective operation of an A-frame APS. The provided ideas have been implemented at the pharmaceutical warehouse of the largest logistics company in Korea. Social implications - The result shows that the proposed idea could save energy consumption and the APS have potential to save labor involvement in picking. Originality/value - It is essential to define the EZs when operating an A-frame APS efficiently, but there is almost no research in this area. This paper focuses on defining EZs, as well as methods to utilize these zones.