What's Your Plan B?

By Mark Roberti

June 12, 2006—Last week, I had the pleasure of participating in a panel discussion at an event put on by TAPPI, the leading association for the worldwide pulp, paper, packaging and converting industries. The other panelists were Craig Harmon, president of Q.E.D. Systems, and Rohit Kori, RFID consultant at Manhattan Associates; the panel was moderated by Mark Brown of RFID4U. A member of the audience asked a simple but important question: What happens when an RFID tag fails while a product is in transit?

We've all heard about UHF tags not functioning. A percentage of tags on a roll are often dead because of manufacturing problems. Most RFID label printers-encoders are able to identify and reject bad transponders, and once tags are affixed to a box, pallet or object, they don't often die. But tags can turn out to be "quiet"—that is, readable only from very close range—or they could be damaged by water, friction or other conditions in the supply chain.


Harmon stressed the need to have a bar code as a back-up. Organizations that have mandated RFID tagging by their suppliers are requiring RFID transponders to be used in addition to existing bar-code and human-readable text for exactly this reason. Still, the idea of having a back-up bar code is not as simple as it might seem.

What if your industry doesn't use Global Trade Identification Numbers (GTINs), on which most Electronic Product Code numbers are based? What if your RFID application uses only unique serial numbers and your bar codes don't have unique IDs? What if you are reading RFID tags at a key point where there is no fixed bar-code reader, and no person typically manning the station to do exception scanning? What if you're creating an electronic pedigree and need to identify individual bottles, but your existing bar codes don't have unique IDs?

Harmon said that the RFID Experts Group he heads for AIM Global is looking into these issues and plans to publish guidelines for companies to follow. These will become increasingly important as RFID deployments scale and failed reads become a more critical issue.

Another interesting issue that came up during the discussion involved rewriting EPCs. EPCglobal is looking at issuing guidelines for how to use the programmable memory in second-generation EPC tags. It's been generally thought that EPCs should be written to the tag and then locked and never written over. However, the discussion revealed that packaging suppliers might benefit from writing unique EPCs to tags on the corrugated boxes they manufacture. When these are shipped to customers, such as Unilever or Procter & Gamble, these companies could use the same tag and overwrite the EPCs with their own EPCs for the product going into the box, using their existing interrogators. This will only be possible, however, if the memory block containing the EPC isn't permanently locked when the EPC is written.

Harmon encouraged the packaging companies in the audience to speak up if they think there is a need to overwrite EPCs on packages, because he is part of the group within EPCglobal that is working on recommendations for how memory on Gen 2 tags should be used. There might be other industries with other scenarios where EPCs need to be overwritten. I encourage people to get involved with EPCglobal now. Rules that could impact your industry are being written every day, and it's going to be hard to change them once they are implemented.

Mark Roberti is the founder and editor of RFID Journal. If you would like to comment on this article, click on the link below.