ORDER PICKING OPTIMIZATION

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World-Class Warehousing and Material Handling

picking travel time has been virtually eliminated. In addition, the same system can transfer storage locations to/from receiving, prepackaging, and inspection operations, virtually eliminating travel throughout the warehouse. Though expensive, the systems may be justified by increased productivity and accuracy. To decide from among these picking schemes, we recommend that a concept be developed, evaluated, and sometimes simulated for each. Beginning with single-order picking and moving to increasingly sophis ticated schemes, incremental justification of the concepts should be conducted. From this justification process, a policy should be selected and implemented. In slotting , we determine for each item its (1) optimal storagemode, (2) optimal allocation of space, and (3) optimal storage location in its appropriate storage mode. As a result, slotting has a significant impact on all the warehouse key performance indicators—productivity, shipping accuracy, inventory accu racy, dock-to-stock time, warehouse order cycle time, storage density, and level of automation. Hence few decisions have more impact on the overall performance of a warehouse than slotting. Yet, when we begin our RightSlot projects, we typically find that fewer than 15 percent of items are slotted cor rectly. Consequently, most warehouses are spending 10 to 30 percent more per year than they should because the warehouse is mis-slotted. Our RightSlot methodology (Figure 8.13) is based on 25+ years of slot ting projects. After looking back on all those projects and all those different types of items—cans, bottles, rolls of carpet backing, brake parts, spools of yarn, computer hardware, vials of nuclear medicine, automotive service parts, paper products, frozen food, and chainsaws—I identified the common denominators of the projects and developed this 10-step slotting methodol ogy and supporting tool to assist in slotting projects. 8.3 RightSlot: Slotting Optimization

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