Order picking is the most critical operation in a warehouse. It involves the scheduling and releasing of customer orders, the picking of items from their storage locations and the disposal of the picked items. Order picking often consumes a large part of the total labour activities and accounts for a substantial percentage of the total operating cost in a warehouse. Therefore the performance of the order picking system has large impact on the performance of a warehouse. The thesis provides models and analyses to support the design and the control of efficient order picking systems with focus on pick-and-pass systems. In a pick-and-pass order picking system, the whole pick area is divided into pick stations (zones) connected by conveyors pieces with order pickers assigned to zones for picking. A customer order is assigned an order bin with a pick list to store articles when it is released to the picking system. The order bin gets on the conveyor, travels from one station to another and only visits a station when pick is needed. When all pick stations where articles have to be picked, have been visited by the order bin, the content is checked and packed. Sorting is needed at the end when multiple orders are batched in one bin. Such order picking systems have many advantages (refer to De Koster 1996) and are widely used in practice. (Author/publisher)
Samenvatting