Figure 5.3: Gravity flflow rack for cartons. (Adapted from “Warehouse Modernization and Layout Planning Guide”, Department of the Navy, Naval Supply Systems Command, NAVSUP Publication 529, March 1985, p 8-17.)
Flow rack is a special type of shelving with shelves that are tilted, with rollers, to bring cases forward for picking (Figure 5.3). The shelves may be 3–10 feet deep (0.91–3.0meters). This means that only one case of a product need be on the pick face, which means that many SKUs can be available in a small area of pick-face. This means highSKU-density, which tends to increase the pick-density, decrease travel, and increase picks/person-hour.
Frequently the picking from flflow rack is accelerated by supporting technology such as a pick-to-light system, by which a centralized computer lights up signals at every location within a bay from which product is to be picked. After the worker picks the appropriate quantity, who pushes a button to signal the computer. There are several benefifits of this: The order-picker is freed from handling a paper pick-list; he does not have to search for the next storage location; and because picking is guided, it is more accurate.
A typical pick rate from flow rack is about 150–500 picks/person-hour, but this varies widely.
Flow rack is restocked from the back, independently of picking. This means that restocking never interferes with picking, as is the case for static shelving, for which picking and restocking must alternate. However, additional aisle space is required to access the back of flflow rack for restocking.
There are several subtypes of carton flflow rack, as shown in Figure 5.4.
• Square front, vertical frame flflow rack is suited to picking full cases, such as canned goods. (This is a specialized use, however, because it requires full-cases in and full-cases out, which suggests excessive handling.)
Figure 5.4: Side views of the shelves of three styles of carton flflow rack. Each successive confifiguration presents the product more conveniently but at the cost of consuming more space. Confifigurations (b) and (c) occupy more horizontal space than (a) and confifiguration (c) also occupies more vertical space.
• “Layback frame” presents the forwardmost carton more fully to the order picker by reducing the overhang of upper shelves, which might otherwise interfere with picking. This style of rack is suited to picking from open cases when those cases vary in size, such as health and beauty aids; but this rack occupies more space than vertical frame rack of equal capacity.
• Layback frame with front-tilted shelves tips the forwardmost cartons forward at a greater angle so that the entire carton is accessible. This is best suited to picking from open cases when those cases are similar in size, such as liquor or books.
阅读全文
收起全文
