Even though it is a frequently useful metaphor, most products do not, of course, flow like incompressible fluids. Instead, they flow more like a slurry of sand and gravel, rocks and boulders. In other words, the product is not infinitely divisible but rather is granular at different scales.
A stock keeping unit, or SKU, is the smallest physical unit of a product that is tracked by an organization. For example, this might be a box of 100 Gem Clip brand paper clips. In this case the final customer will use a still smaller unit (individual paper clips), but the supply chain never handles the product at that tiny scale.
Upstream in the supply chain, product generally flows in larger units, such as pal- lets; and is successively broken down into smaller units as it moves downstream, as suggested in Figure 2.2.
Thus a product might move out of the factory and to regional distribution centers in pallet-loads;
and then to local warehouses in cases; and finally to retail stores in inner-packs or even individual pieces, which are the smallest units offered to the consumer. This means that the fluid model will be most accurate downstream, where smaller units are moved.
Figure 2.2: A product is generally handled in smaller units as it moves down the supply chain. (Adapted from “Warehouse Modernization and Layout Planning Guide”,Department of the Navy, Naval Supply Systems Command, NAVSUP Publication 529,March 1985, p 8–17).
2.2
Units of handling 产品的作业单位
Even though it is a frequently useful metaphor, most products do not, of course, flow like incompressible fluids. Instead, they flow more like a slurry of sand and gravel, rocks and boulders. In other words, the product is not infinitely divisible but rather is granular at different scales.
尽管这是一个常用的比喻，但大多数产品当然不会像不可压缩的流体那样流动。相反，它们更像沙子、砾石、岩石和大圆石的泥浆。换句话说，产品不是无限可分的，而是有着不同等级的颗粒度。
A stock keeping unit, or SKU, is the smallest physical unit of a product that is tracked by an organization. For example, this might be a box of 100 Deli brand paper clips. In this case the final customer will use a still smaller unit (individual paper clips), but the supply chain never handles the product at that tiny scale.
库存单位，或SKU，是组织所跟踪的产品的最小物理单位。例如，这可能是一盒100个得力牌回形针。在这种情况下，最终客户将使用更小的单位(单个回形针)，但供应链从未处理过如此小的规模的产品。
Upstream in the supply chain, product generally flows in larger units, such as pal- lets; and is successively broken down into smaller units as it moves downstream, as suggested in Figure 2.2.
在供应链的上游，产品通常以较大的单位流动，如托盘；并且在它向下游移动时被陆续分解成更小的单元，如图2.2所示。
Thus a product might move out of the factory and to regional distribution centers in pallet-loads; and then to local warehouses in cases; and finally to retail stores in inner-packs or even individual pieces, which are the smallest units offered to the consumer. This means that the fluid model will be most accurate downstream, where smaller units are moved.
因此，产品可能会以货盘的形式从工厂转移到区域配送中心；然后以箱装的形式运送到当地仓库；最后是以内包装甚至是单件的形式运送至零售商店，这是提供给消费者的最小的单位。这意味着流体模型在产品以小最单位流通的供应链下游的应用最准确。
