Tracking and tracing products—and the parts that make up systems—will increase in importance across a number of industries, says Holger Schoenherr, Head of the RFID Center of Competence, Siemens Automation & Drives, (www.automation.siemens.com). One reason is safety, where it is increasingly necessary, says Schoenherr, “to prove that everything that you say is in the vehicle is actually there.” What’s more, it integrates manufacturing operations.
For example, he suggests, moving from barcoding to attaching RFID tags to completed systems and major components is a way of using data to aid flow. BMW is using RFID tags to speed wire harness distribution to its 3 Series assembly line. The harnesses are built by the supplier on a JIT basis according to a production broadcast from the plant, then bagged and tagged with RFID transponders. “Readers are integrated into the conveyor system at the plant,” says Schoenherr, “and the proper wire harness is automatically routed to the correct vehicle.” Not only does this system reduce costs by cutting mistakes and speeding process flow, he says it increases BMW’s flexibility by allowing last-minute production changes to be accommodated without having to sort through tens or hundreds of wire harnesses barcode by barcode.
Ask the folks at Siemens about RFID tag costs compared to a typical paper barcode tag, and you will get a direct answer: “RFID is about 13 cents more per tag.” It’s one reason 20-cent RFID tags are scarce compared to their barcode cousins. However, Schoenherr claims this is false economizing, while admitting Siemens is working to lower costs and add functionality. “We are experimenting with a tag that replaces the silicon semiconductor chip with a ‘printable’ polymer version that is as capable and more robust,” he says. This development is taking place in parallel with a merging of RFID and sensor technologies onto a single tag.
“As the vehicle goes down the assembly line, for example, it will be possible to determine if all of the airbags are in place
and functioning properly, see whether the build sheet and vehicle specification agree, and track the part back to its component pieces and assembly conditions,” he says. The latter, he suggests, would include a feedback loop that would monitor the build conditions based on pressure, temperature, or other critical factors. “It’s not out of the question,” he says, “to produce a reporting system that would be capable of alerting a machinist that a tool is about to fail based on the pressure the tool exerts during the machining process, or—looking up the production process—to set off an alarm if a part or module is installed incorrectly or with too much force.” Recounting Siemens’ own experience with switching from a barcode to RFID system in a production facility—initial costs increased 35,000, but production jumped 70,000 units per year with no other changes and paid off the initial investment within two years—Schoenherr says this is only one reason to make the switch. “In the near future, either the government or your customer—or both—will demand proof that your product is as you have presented it."