ORDER PICKING OPTIMIZATION

Chapter eight RightPick RightShip: Order Picking and Shipping

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fully distributed evenly along the flow-rack pick line. The most popular flow-rack items are located in the golden zone for the flow rack, the level of the flow rack at or near waist level. The remainder of the items falls naturally into bin shelving. To minimize travel time, the bin-shelving items with the greatest pick density are assigned to locations along or near the pick line. This slotting scheme alleviates any congestion prob lems and allows nearly 75 percent of the picks to be executed along the main pick line. The reserve stock for the gravity-flow lanes is housed in double-deep pallet racks along the back wall. Batched replenishments are executed along the back of the flow lanes. Reserve stock for the bin shelving is conveniently located in single-deep pallet racks along the sidewalls. This slotting and operating scheme yielded a 100 percent improvement in productivity and response time with minimal capital investment and risk. In both operator-to-stock and stock-to-operator systems, sequencing pick location visits can reduce travel time and increase picking productiv ity dramatically. For example, the travel time for a person-aboard ASRS picking tour can be reduced by 50 percent simply by dividing the rack into upper and lower halves and visiting pick locations in the lower half in increasing distance from the front of the rack on the outbound leg and in decreasing distance in the upper half of the rack during the inbound leg (Figure 8.20). Location visits also should be sequenced in walk-and-pick systems. In case picking operations, when an order may occupy one or more pallets, the picking tour should be sequenced to allow the picker to build a stable load and to reduce travel distance. A major distributor of photographic supplies uses an expert system to solve this complex problem (Figure 8.21). 8.4 RightRoutes: Pick-Tour Sequencing

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