Real-time holonic scheduling: Making warehouse picking more efficient
The increase of labor costs due to the expansion of the e-commerce market is a serious problem in logistics warehouses. In these warehouses, order picking accounts for about 55% of the labor costs. To reduce the order picking cost, automated guided vehicle (AGV) picking systems have been developed (Fig. 1) [1]. AGVs transport the entire shelves including the required items (inventory shelves) or shipping boxes (sorting shelves) to a picking station (PS) at which a picker works. The picker picks the ordered items from the inventory shelves and sorts them into the shipping boxes in the sorting shelves without walking around the warehouse, which improves the productivity of his picking activity. The AGV picking systems scale the throughput easily by changing the number of AGVs, shelves, and PSs. In conventional systems, the sorting shelves are fixed or are transported only after the completion of the sorting work of the shelves. These systems lack shelf-transport task scheduling flexibility.
