Dynamic Slotting, Automated Replenishment of Pick Modules Boost Throughput

Warning_signWarning: This is not your standard article on slotting.

Sure, when you hear “slotting,” you might think “torture.” Even Bob Trebilcock, Executive Editor of Modern Materials Handling magazine, likens slotting to an unkept New Year’s resolution in this article, saying: “It’s a great idea on paper, but few warehouse managers actually follow through on that resolution in a disciplined way.” That’s because conventional slotting can be time- and labor-intensive, as well as tedious.

Simplified, conventional warehouse slotting in a manual operation involves an analysis of stock picking unit (SKU) data, usually from the past 12 months, to determine where inventory should be stored in the facility. SKUs are ranked based on their pick frequency (velocity), quantity, sizes, weights, and family relationships (toothpaste and toothbrushes are frequently ordered together, for example).

Depending on their classification as a fast-, medium- or slow-moving item (often called A, B and C movers), slotting calls for products to be stored in different locations. Items picked most often are located in areas that are easily accessible to pickers, such as forward pick zones and low level flow rack; slower movers are placed in less accessible areas that require travel and/or a forklift to access them. The payoff is quantified by a reduction in operator walk or drive time, better pick accuracy, and improved utilization of both warehouse space and labor. Conventional slotting is often a periodic activity, conducted quarterly or annually (if at all, to be honest—remember “tedious” and “torture”?).

This article, however, is about dynamic slotting. Dynamic slotting modules, either integrated into a warehouse management system (WMS) or as a functional add-on, optimize the medium and slow-velocity movers within a forward pick zone in real time, continuously. Ideal for order fulfillment operations that either fill high volumes of one- and two-line direct-to-consumer orders (like those found in e-commerce), or handle a lot of rapidly changing inventory in picking, the goal of dynamic slotting is to frequently shuffle inventory through designated pick modules to keep pace with changing demand while optimizing throughput.

Picture17To do this, the system evaluates orders in advance of their release to pickers (the software can be configured to automatically trigger the review, or to prompt the operation’s management when certain key metrics indicate that the process should be authorized). After parsing through the open orders and cross-referencing them against current pick zone activity, the software’s algorithms determine which SKUs should remain in the zone, which should be replaced, and in what amounts.

If the dynamic slotting system is deployed in conjunction with an automated storage and retrieval system (AS/RS) to create a high performance picking system, automated replenishment of the pick faces can occur. Depending on the volume of orders handled by an operation, pick modules can be dynamically stocked on the fly, or by wave, by shift or by day (vastly more often than conventional slotting).

Dynamic slotting is particularly ideal for facilities that store a high number of medium- to slow-moving SKUs. Giving each of those SKUs its own pick location would be a highly inefficient use of space and labor.

Conversely, storing those products in a highly dense, automated material handling system and delivering them as needed to a picker in a designated forward pick zone saves space, minimizes travel, and increases pick rates from 100 to as high as 500 lines-per-hour. That’s because the WMS works with the dynamic slotting software to group like orders for release at the same time, allowing multiple orders to be filled simultaneously for even higher throughput. Further, to accommodate order spikes due to promotions or seasonal peaks, dynamic slotting and automation can support a temporary pick zone set up to handle the additional volume.

Will dynamic slotting work for your operation? Call us at 616.977.3950 to speak with a warehouse planning specialist about your order fulfillment process and how dynamic slotting can help you keep pace with changing order volumes and demands.

About Jason Perks

Jason Perks is a regional sales manager at the North American headquarters of viastore systems in Grand Rapids, MI.
He has been in the material handling industry for over 15 years. Jason holds a degree in Mechanical engineering from Michigan Tech. University.

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