RFID Clocks In

Jan. 1, 2006
RFID has deep roots in manufacturing, but Wal-Mart’s supply-chain mandate is breathing new innovation—and lower costs—into this decades-old technology

Singapore-based contract manufacturer Flextronics uses radio frequency identification (RFID) technology in its manufacturing for a number of clients, including Hewlett-Packard (H-P), Motorola and Xerox. In the assembly of H-P printers, for example, printer housings include an RFID tag that is encoded with product ID, manufacturing date and all of the components it requires. As the housing moves down the assembly line, the tag indicates what component needs to be added next. Once the component is attached and tested, an RFID transceiver writes data to the tag indicating the component was added and that it was tested.

The data is then sent over Ethernet to an Opto 22 industrial controller, which validates that the component as been added and tested. The controller then sends commands to conveyors and other systems to move the printer to its next stage. If the tag data received by the controller indicates that a part is missing or a test has failed—or a test wasn’t conducted at all—the controller routes the printer back to start the assembly process over again. If a severe problem exists, the controller sends the printer to an area designated for defectives.

The RFID system catches errors earlier than they would be caught by a manual system. The errors are noted on the tag, so re-running the printer through the botched stage can correct the problem in an automated process. If the error requires intervention, the printer is routed—again automatically—to an area where technicians can read the tag and find out exactly what went wrong in the assembly process. Welcome to the new world of RFID in manufacturing.

Deep history

RFID is getting plenty of attention in the trade press because of its recent use in the consumer packaged goods supply chain. But RFID has a long and deep history that precedes recent attention. The technology was first developed and used by the U.S. Air Force during World War II, when RFID tags were placed on U.S. warplanes so ground operators could distinguish them from enemy planes.

When the war was over, RFID technology moved into the manufacturing plant. For the past two decades, RFID has been used in a number of industries, most notably in automotive, semiconductor and aerospace manufacturing. The benefits of RFID in manufacturing include the tracking and tracing of assets and goods in process. More recent applications include use of RFID in the assembly process to make sure the right part or process is completed accurately at the right time, as in the Flextronics example. RFID is also being used by the pharmaceutical industry to prevent errors and stymie counterfeiting.

Tags come in both passive and active forms. Passive tags don’t send signals and thus don’t require a power source. Some passive tags simply carry ID data for a part or container. Many passive tags also have read-write capability, which lets the user add new information. “Passive tags are more abundant because they are used for inbound logistics and in-process tracking in manufacturing,” says Mark Hamblin, director of manufacturing solutions at Matrikon Inc. an Edmonton, Alberta, Canada, automation vendor.

Active tags emit a signal than allows operators to “see” them even if they are not passing close to a reader. Active tags are more expensive and are typically used to track pricy assets such as trailers full of goods or expensive mobile plant equipment. “Since active tags are more expensive—$25 to $85 per tag—the asset they’re used on has to be more expensive,” say Hamblin. “Active tags are used in oil and gas, where you’re moving around expensive equipment that needs to be located immediately.”

In 2003, Wal-Mart Stores Inc., the giant Bentonville, Ark.-based retailer, told its 100 top suppliers they would have to attach passive RFID tags to pallets and cartons beginning Jan. 1, 2005. The U.S. Department of Defense (DoD) and numerous major retailers followed with their own mandates. The resulting supply chain crash course in RFID has given the technology greater visibility while driving down costs. “Individual companies have to step up and push the adoption of a technology in order for it to take off,” says Kevin Prouty, senior director of manufacturing solutions at Symbol Technology Inc., a supplier of auto ID and mobile computing products based in Holtsville, N.Y. “For bar-coding, it was Ford, GM and Chrysler. For RFID, it has been Wal-Mart and the DoD.” The push from large retailers and the DoD has driven the price for a passive tag down to the 10 to 20 cent range for quantities in the millions.

The mandates have also brought RFID to the attention of plant managers. Perhaps the most significant difference between the use of RFID in the supply chain and the use of RFID in the plant has to do with why RFID is being adopted. In the supply chain, suppliers have been forced to adopt the technology used by their largest customers. In the plant, RFID is being adopted because of its direct benefits. “The biggest difference between RFID in the supply chain and RFID in manufacturing is that RFID in the supply chain is driven by mandates, while RFID in manufacturing is driven by ROI (return on investment),” says Chantal Polsonetti, vice president of manufacturing advisory services at ARC Advisory Group Inc., in Dedham, Mass.

RFID standards

Until recently, RFID was used almost exclusively in closed-loop, inside-the-four-walls networks. The Wal-Mart and DoD applications, however, require an open-loop network in which suppliers pass off pallets and cartons to their retailers, and both companies must be able to read and assimilate the data. So standards have become critical. The RFID standards group, EPCglobal Inc., of Brussels, has developed two sets of standards—Gen1 and Gen2—that companies can use to share RFID data. “One of the issues with RFID in the past has been the lack of standards, which makes it difficult to pass tags from supplier to manufacturer,” says Damon Bramble, general manager for the RFID Solutions Center at Alien Technology Corp., a vendor of RFID products based in Morgan Hill, Calif. “That issue has been solved on the passive side by EPCglobal.”

The new interoperability provided by the standards offers manufacturers new ways to work with suppliers that can potentially increase collaboration and speed the manufacturing process. “At Boeing, the manufacturing managers have a vision of using RFID to collaborate with their suppliers and reduce the amount of time it takes to produce an aircraft,” says Dave Hanny, director of hardware interfacing products at Brooks Software, a division of Brooks Automation Inc., in Chelmsford, Mass.

Carmaker Toyota Motor Corp. uses RFID technology at its South African plant to track its vehicles as they move from production to shipment. Toyota applies an Alien RFID tag to each vehicle during production. The cars are tracked as they move through the assembly plant and into the distribution yard. The accurate tracking helps Toyota streamline the movement of the vehicles from production to shipping, and it also accelerates the invoicing process.

The tags Toyota uses are inexpensive, because they are passive and don’t require read-write capability. The tags use the EPCglobal standard, so they can be read for tracking by the shipper as well as by the lot that eventually receives the vehicle. John Stoop, senior plant manager at Toyota’s South African plant, expects the RFID system will quickly pay for itself. “This will both accelerate and streamline vehicle shipping and invoicing,” says Stoop. “Anticipated savings in time-to-cash should offset the cost for this RFID project.”

Other major RFID track-and-trace applications include asset management and the tracking of goods in the manufacturing process. RFID is being used to make sure the right materials make it to the right place at the right time and in the right quantities. In sensitive manufacturing such as pharmaceuticals, RFID-tagged supplies can prevent costly—and potentially dangerous—mistakes. An RFID trail can also provide product pedigree information required by the U.S. Food and Drug Administration (FDA). “There is definitely a place for RFID in getting the right ingredient to the right place at the right time,” says Alien’s Bramble. “With passive RFID, you can potentially stop a process if the right ingredient isn’t there.” He notes that the pharmaceutical industry is using RFID to stop the sale if the right dosage isn’t matched with the right patient. “RFID provides an air-tight system for ending errors,” Bramble contends.

Data backbone

When used in an assembly line, the RFID tag can contain a host of data for customizing products, making the manufacturing process more flexible, as well as more streamlined. “The RFID tag can be the backbone of your plant data,” says Matt Ream, product manager at Zebra Technologies Corp., a supplier of printing products for bar code labels, including “smart labels” with embedded RFID tags, based in Vernon Hills, Ill. “At the beginning of an auto line, the tag can carry everything you want to do to the vehicle, what kind of paint, seats, even the vehicle ID number.”

Though RFID has been used in manufacturing for decades, the burst of interest in RFID that came with the Wal-Mart mandate has fostered a new wave of innovative uses for RFID in manufacturing. RFID tags are now being used to track assets, deliver product customization data, and track products in process. The FDA has pushed the use of RFID in pharmaceutical manufacturing to help create an audit trail that can thwart counterfeiting, while making sure the right patient gets matched with the right prescription. Finally, new RFID standards are giving RFID a boost as a tool for collaboration between manufacturers and suppliers.

For more information, search keyword “RFID” at www.automationworld.com.

See sidebar to this article: Getting the Right Part to the Right Place