The layout of the warehouse determines the cost associated with each storage location. In the layout of Figure 6.10 the average positions of receiving and shipping are in the middle of opposite sides of the warehouse. This is sometimes referred to as a flow-through configuration because all product flows from one side of the facility to the other. As a result all the storage locations along one side of an aisle are equally convenient.
Now imagine how the convenience of the storage locations changes if the shipping and receiving doors were both moved to the right. Then storage locations to the left would become less convenient and the locations on the right more convenient; but the quality of the very best locations would not improve, while the quality of the very worst locations would become strictly worse. The result is that the layout would be absolutely less efficient.
If both receiving and shipping are on the same side of the warehouse this induces a different economic terrain within, as shown in Figure 6.11. Because product flows in and out the same side of the warehouse, this is sometimes referred to as a U-flow configuration.
Now the best storage locations, which are at the middle of the common receiving and shipping dock, are very convenient indeed because a location that is close to receiving would also be close to shipping. However, there are relatively few such prime locations and there are more inconvenient locations than before; and the least convenient locations, at the far top corners are even less convenient than the least convenient of Figure 6.10.
Which layout is better? In this case, as with so many of the design decisions, it depends on the populations of SKUs passing through the warehouse. If there are few very fast-moving SKUs, as is typical in cosmetics, apparel, or other fashion businesses,
it may be more efficient to put receiving and shipping on the same side of the facility,because the savings from the few very convenient locations may offset any loss due to the greater number of less convenient locations.
Here are some characteristics of each type of layout:
• U-flow configuration
– Receiving and shipping located on same side of the warehouse
– Makes the most convenient locations still more convenient, less convenient locations even worse.
– Appropriate when product movement has strong ABC skew (that is, when very few SKUs account for most of the activity)
– Provides dock flexibility for both shipping, receiving: If one experiences a surge of activity, can make use of additional doors from other function.
– Permits more efficient use of fork lifts: When a forklift reports for an assignment, he may be given a put away and a retrieval, matched to reduce dead-heading.
– Minimizes truck apron and roadway
– Allows expansion along other three sides of warehouse.
• Flow-through configuration
– Receiving and shipping on opposite sides of the warehouse
– All product flows in the same direction so there is less opportunity for interference.
– Makes many storage locations of equal convenience.
– Conservative design: More reasonably convenient storage locations but fewer that are very convenient.
– More appropriate for extremely high volume.
– Preferable when building is long and narrow
– Reduces any efficiencies that might be gained from dual cycle transactions
Figure 6.10: When receiving and shipping are located at opposite sides of the warehouse there are many locations of equal convenience, and with the most convenient on a line between shipping and receiving. (The darker locations are the more convenient.)
Figure 6.11: When receiving and shipping share the same dock (at the bottom in this example) then there are a very few, very convenient locations as well as some very inconvenient locations. (Darker shading indicates more convenient locations.)
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