RFID tag placement: unit-load tagging, on a pallet or otherwise, is not so simple as it looks. After all, someone has to be able to read it once the shipment is delivered

Frontline Solutions, June, 2004 by Brian Albright

At United Kingdom express carrier Lynx Express, TrenStar's RFID tags are tracking metal roll cages through the company's superhub at Nuneaton, saving the carrier around $178,665 in misroutes. The system has also improved visibility and management of the roll cage fleet.

TrenStar is partnering with O-T-D Corp. to provide RFID-ready aluminum containers for the synthetic rubber industry, and TrenStar has formed a partnership with Matrics Inc. to develop RFID solutions for reusable containers for the food and chemical industries.

AIS, meanwhile, has developed a system called KartKeeper for tracking metal carts used to distribute plants in a closed-loop application. Two companies, Kentucky-based Colorpoint and Illinois-based MidAmerican Growers, are using the system to track these carts to such retailers as Wal-Mart and The Home Depot.

To get as close to a 100% read rate as possible, the AIS team had to overcome interference from the metal carts, ambient noise in the environment, and water from the plant containers. "We knew that the tags wouldn't read if they were sitting in water," says AIS' Nolan. "But even if water is just nearby--within a very small margin--they still don't work."

The material handling industry is still mostly in the investigative stage with RFID. As standards develop and the technology improves, most think that RFID tags will become a standard part of returnable containers. "The truth is, for these types of RFID projects, the cart needs to pull the horse. Studies have shown that when mobile assets are retrofitted with RFID tags in the field, the cost to attach them to the container is 10 to 15 times higher than it would be during the manufacturing process," says John Fontanella, vice president for research at AMR Research Inc.

Quality Control

Attaching the tag in the right place is only half the story; someone has to be able to read it once the shipment is delivered.

For manufacturers taking a compliance-only approach to RFID adoption, with little immediate interest in reading the tags in their own operations--a practice now crudely referred to as "slap and ship"--problems may still arise. Even with proper placement and engineering, there's no guarantee that the functioning tag you put on a case or pallet will be readable by your end customer. Some analysts have predicted a whole new wave of retailer chargebacks as a result of unreadable RFID tags.

Category-level standards will help--for instance, best practices for tagging cases of canned vegetables--but they will take time to develop.

Quality control in the shipping department will also play a role. Any given batch of RFID tags is bound to include a few duds--and with some of the UHF tags, the failure rate is discouragingly high, although these numbers are improving.

In the bar code world, ANSI specifications provide a lowest common denominator measurement so that manufacturers can (usually) print their labels legibly and customers can (usually) read them with a bar code scanner. Bar code verifiers--some stand-alone, some built into label printers--measure quality against these standards.