Probably the most important opportunity to improve the distribution center productivity and performance quality is through improving the quality of the data you use to operate it. Maintaining high-quality data is required for an effective warehouse management system (WMS), but you can also benefit from improved data quality even if you do not have a WMS. This is the second column in a series in which I will describe some ways you can clean up your data, keep it clean and improve your daily operations.
The best place to start to improve data quality is with the SKU data, specifically the weight, dimensions and pieces per carton. This data has the biggest impact in your operation, from stocking, to replenishment, picking, packing and shipping; each of these operations is performed better when the SKU data is correct.
First, you need to get the data clean. One way is most time-consuming and comprehensive. When we know the data is substantially wrong for many SKUs, gathering the SKU dimensions, SKU weight and SKU units per case, and recording them as a part of a regular or special inventory process ensures that at one point in time the data will be correct. However, I worked with one company that had primarily used this way as a part of its annual inventory in June and it found that by late November, the time for the last push for Christmas selling, without any other supporting processes, the data had deteriorated so that pick errors and inventory inaccuracy made order processing almost impossible.
So once you have the data clean, or if the problem is not large in your operation, you need the right maintenance procedures to keep the data from deteriorating. To keep the data accurate we have introduced three maintenance processes. In the first, a proactive process, you can add a data quality check to the receiving process. To do this, we add the appropriate data fields to the receiving check-in document for each receipt. When the receiving clerk notices that a field on the form is blank, indicating the data is not in the system, or the data printed on the document seemed inconsistent with the material as received, the receiving clerk is asked to fill in the blanks or correct the data on the document. This approach has proved to be efficient, has kept the data much more accurate and is used in many warehouses, both with and without a WMS.
One way to increase the accuracy of the data collected and entered, which has been successful for both the inventory and receiving, is to use a measurement device that can automatically capture the SKU bar code, weight and dimensions when you place the item on a platform. Then after entering SKU number (or bar code) and the pieces per carton, place the item on a platform and the system will record the data on a disk for easy movement to your system. Some organizations have seasonal or constantly changing inventory and choose to purchase the measuring equipment and keep it on a cart in the receiving dock area for easy access. Others organizations, when initially setting up the data or doing a major audit of the data, rent the equipment for a month and manage the ongoing data collection manually. One of the sources for this equipment is the Quantronix Company (in Utah).
The second process developed out of our recognition that, with all the proactive effort, data problems slip through. So we recommend a reactive process to correct the problems when they are found by the picker, replenisher, packer, shipper, customer or any place in the system. Typically we find that the number of SKUs found each day with data problems is small and the tendency is to wait until the number gets large or significant and then to correct them all. This approach will not serve you well. You will be much better off to do a little of this work every week. Your productivity and customer relations will show a noticeable improvement.
We have found two staffing approaches work well to resolve the remaining SKU data problems. In the first, add the data correction task to the work of the person responsible for inventory accuracy. Typically this additional workload will not require a significant amount of time. If it takes a lot of time in your operation, you probably have another source of inaccurate data you need to correct at the source; perhaps your receiving crew is not taking care of their responsibility, or the buying staff is providing inaccurate data. The general direction is proactive: to correct the data collection and entry process at the source, and minimize the reactive work to fix the data and the problems bad data create later.
The second staffing approach is to rotate the responsibility among the order-entry staff. This has worked in several companies where there are regular telephone order-entry cycles through the day. The OE staff enjoys getting away from their desks for a while and actually seeing the warehouse and merchandise increases exposure to your inventory, and the warehouse operation can help them become more effective. This approach may not work for you, but I hope the idea prompts you to consider an alternate creative approach that will work for you.
The third process -- analyzing the data -- can point you to potential problems before you hear from a picker or a customer. In this approach, we regularly (perhaps once every two weeks) run a report from the SKU master file data listing all the SKUs where the weight, dimensions or units per case fields are empty or filled with 1’s or 0’s. Data like this needs to be verified or corrected.
I encourage you to take the initiative to keep your data correct. You may not be responsible for it, but if it is wrong you are the one to suffer. So you might as well begin to do the work.
Don Benson, P.E., has been consulting to retail, wholesale and manufacturing organizations for more than 25 years. His practice focuses on improving the effectiveness of warehouse and distribution operations. His office is in Oakland, California. He can be reached at[email protected]or 510-482-3436.