Improving Order Accuracy

Apr 11, 2007 8:57 PM  By

“This isn’t what I ordered.” You ordered your eggs scrambled, but they arrived poached. Or worse yet, you got a plate full of lima beans. Blech.

Just as in a diner, order-fill inaccuracies in a distribution center can disappoint or infuriate the customer. What’s more, they can cost the seller dearly in terms of customer loyalty, returns processing costs, and lost revenue.

The following are a handful of simple steps and concepts to help increase outbound order-fill accuracy in your distribution center.

The Basics
I’m still surprised by the number of DCs that operate purely on a “head knowledge” basis with respect to where items are located. Some operate without location numbering schemes at all, while others use a pick process that does not tell the picker where to go, only what item to retrieve. Even with a seasoned workforce, this is all but asking for picking accuracy errors.

Every storage or picking location in a warehouse should have a discrete identifier. Wherever practical, make certain that inventory is in discrete locations. In other words, a specific quantity of a specific SKU should be in a specific location, both physically and systematically. In most cases, it makes sense to reduce or eliminate the practice of locating multiple SKUs in a single location. A picker shouldn’t have to search and choose between items in a single location to find what he needs.

Measurement
Track accuracy levels for each picking employee on a regular basis. When an error is found, record the employee’s name, the SKU, the location, and the type of error (wrong quantity, wrong SKU, pick omission).

Conduct statistical sampling of outbound orders for accuracy. Every picker should know that a percentage of his work will be checked on a daily or weekly basis and that he must maintain a minimum acceptable accuracy rate. Pickers should not know which orders will be checked, and the checker should not be the same person who picked the order.

As this information is compiled over time, address trends that develop with problematic employees, problematic SKUs, and areas or processes that tend to produce the most errors.

The Dreaded UOM Problem
Unit of measure (UOM) problems are widespread across many industries. Pickers, especially new employees, are often left to their own devices when having to interpret pick quantity instructions. For example, an order filller may see “Pick 12” on his pick document and subsequently pick 12 boxes of a SKU when he should have picked two boxes, each of which contains six units.

You can minimize this problem by introducing enhanced descriptions on the pick documents/screens as well as on the location labels. Information such as quantity per carton and definitions of eaches, units, and cases should help employees better understand exactly how much to pick.

Incentives
If your DC has an incentive program, include accuracy as a component of incentive pay calculation. For instance, a picking employee must achieve a minimum order-fill accuracy rate before he can earn incentive pay, regardless of volume of work processed or level of performance achieved against a standard.

Technology
The accuracy benefits of voice-directed picking, pick/put to light, and RF picking, among other technologies, are well documented. However, if your DC does not use any of these, you can probably still leverage your existing technology or make small upgrades to help increase outbound order accuracy without spending much capital.

To compare actual vs. expected weight of a carton or a tote, use check-weigh functionality. Check weighing of totes or cartons is done with scales, whether integrated as part of a conveyor system, or stationary stand alone scales. Weights are captured then compared against expected weight for that package or tote.

This can be done for both full-case and broken-case operations. Any weight that is not within a reasonable weight threshold should be checked for accuracy.

Make sure items with similar part numbers or SKUs that look alike are not slotted in pick locations adjacent to one another. Some software slotting packages can handle this automatically, but even if you do not use software-based slotting, you need to address this.

If you operate in a conveyorized, full-case pick environment, consider using vendor/supplier barcodes on the boxes to assist in accuracy checks. Many companies scan two separate labels for every box picked out of their full-case modules: The picker-applied shipping label is scanned to make sure all cartons of an order have been seen, and the second label, a vendor-supplied SKU barcode, is scanned to guarantee that the picking label was applied to the correct SKU.

Information is key in reducing picking inaccuracies. Understand where your errors are coming from and what is causing them. Then take measures to eliminate the source of errors. All the ideas above have been used successfully across a wide variety of industries to increase outbound order accuracy without large capital outlays.

Pat Brown is director of engineering for Long Grove, IL-based TZA Consulting.

Related articles:

Best Practices in Fulfillment: Picking and Packing

Now Listen to This: Voice-Directed Picking