Problems With RFID Data

Oct. 1, 2005—For manufacturers, the great promise of radio frequency identification—or more specifically, Electronic Product Code technologies—is the ability to get better information about the location of their products within the supply chain. In particular, many manufacturers see EPC as a way to gain better insights into what's happening downstream in a retailer's distribution centers and stores. But to their dismay, the quality of the data coming back from retailers has not been very good.

"We're very disappointed in the data we're getting back," says an RFID project leader at a major consumer goods manufacturer who did not want to be identified for fear of angering his retail partners. "What we're getting just doesn't reflect what's happening in the back of the store."

Some manufacturers have begun to look to third parties to help filter and analyze data coming back from retailers.

Tags on pallets and cases are interrogated when they arrive at distribution centers, when they leave DCs and when they arrive at the backs of stores. Some retailers are providing tag IDs and the time and location the tags were read to manufacturers, so they can see the flow of their products through the retailers' supply chain. In most cases, however, the quality of the data retailers are supplying is not high for several reasons.

One problem is that retailers and manufacturers are not getting the same read rates. Manufacturers say that they are able to achieve read rates of 80 percent to 100 percent on products they ship out to retailers (the low end reflects poor reads on pallets of product that are not "RF friendly"). But manufacturers find the read rates in retail DCs and stores to be far lower. They might ship 100 cases to a retailer and find that no more than half of the cases were read.

The difference can be attributed to the placement of tags on products and the orientation of interrogator antennas. Manufacturers can apply tags on cases in the position that is easiest and most advantageous to them. And they can set up interrogator antennas in the optimal configuration to ensure the highest read rates are achieved when interrogating tags on conveyors, palletizers and stretch-wrappers, and at dock doors. But retailers must deploy interrogator antennas in configurations that can read tags on a wide variety of products, with tags placed in many different locations on pallets and cases arriving from more than 100 different manufacturing sites.

Another reason the read rates are lower in retailers' facilities is that manufacturers typically purchase tags of a single protocol, either Class 1, Class 0 or Class 0+. Retailers must be able to read all these protocols as cases move rapidly down a conveyor in random order. To do this, retailers deploy multiprotocol interrogators, but these can miss tags on cases if, say, they are querying Class 1 tags and a case with a Class 0 tag moves into the read zone.