Radio frequency identification tags grow in popularity as warehouses find new uses for the technology.

In a world that is becoming evermore dependent on the use of technology, we are seeing high-tech solutions everywhere. In fact, radio frequency identification (RFID) tags are gaining popularity not only in industry, where they can be of great use in warehouses, but in everyday walks of life.

Take, for example, the several libraries in the United States that now allow consumers to check out books without the aid of a librarian. RF tags monitor when the book was checked out, and where it is.

In Vejle, Denmark, RFID technology gives bus passengers expected arrival and departure times and platform numbers well in advance -- similar to the information available to passengers waiting for flights in airports. The information, provided on displays at platforms and terminal buildings, monitors 149 buses operating 13 city and 22 regional routes, with a total of 800 arrivals and departures every day.

Similarly, tollbooth lines are becoming a thing of the past on major U.S. highways, as smart passes -- bar codes attached to the windshield of a vehicle -- record the tolls as vehicles zip through electronic tollbooths.

More and more RFID applications are being found within the warehouse industry. RFID tags are typically seen as a replacement for bar codes. The systems are designed to identify "tags" as they pass by the system's reader. The tags react to a radio interrogation signal from the reader with its ID. The use of this technology is expected to skyrocket as it becomes more affordable.

The advantages of RFID are numerous. For example, RFID does not require a direct line of sight. The tags can be read through non-metallic materials. RFID tags can withstand sunlight, water, cold, dirt, grease, heat and corrosive chemicals. And RFID technologies include read/write memory, providing an "electronic manifest" or "wireless smart-card" capability.

RFID systems usually come in two forms: active and passive. Active products require a battery; passive systems do not. Active systems are typically more expensive, with the constraints largely driven by battery costs and capabilities. In general, active tags tend to support read ranges that cannot currently be achieved without a battery or are designed to be read on vehicles moving at high speeds. Passive RFID tags get operating power from the reader through the air, albeit at relatively short ranges. Prices of passive tags have been dropping as the technology becomes more popular.

Off the shelf

"The percentage of warehouses using RFID technology is tiny," says bar-code guru Rick Bushnell, president of Quad II in Chalfont, Pa. "But it's growing pretty significantly."

And for good reason. A warehouse worker using RFID technology can scan an entire area of pallet racks in about 30 seconds, rather than taking as long as three or four minutes to scan pallets individually.

Another big advantage for warehouses is the ability to alter space allocation. Many warehouses waste great amounts of labor moving and stocking products in a similar location. Drive shafts, for example, may all be located in one section of the warehouse, while steering columns are located in another. However, RFID technology allows warehouses to store product almost anywhere, to move it on a moment's notice, and to find it instantaneously.

"We've been told by some of our customers that the change in strategy for the warehouse -- particularly with larger or bulkier parts -- can save them 10% to 20% on warehouse space," says Turner. "When you're dealing with 500,000 sq. ft. or more, 10% to 20% drives return on investment pretty quickly."

Ray Chatfield, a business analyst at USCO Logistics, Naugatuck, Conn., says his firm is in the process of rolling out RFID technology at several sites. The firm's image is enhanced by using the latest technology, but Chatfield says the real benefit is in customer service.

"RFID improves our customer-service position, and if we get a better service level, we get more business," he says. "If one of our customers is interested in knowing exactly how close a rush order is to shipping, RFID gives us visibility between the release of the order to the floor and confirmation of the shipment. We can see how much of an order is assembled for shipping, and we can make a good estimate of when it will be ready. With a paper-based system, it's in limbo until they get shipment confirmation."

With standard bar-code technology, warehouses are able to track when a container or pallet has entered the facility. However, these days that's not enough, especially in larger facilities.

"If you have a distribution center that may be hundreds of thousands of square feet, people want to know where the product is," says Tom Turner, vice president of WhereNet Corp., a California-based provider of real-time location systems. "We can tell them exactly. This really provides visibility through the supply chain at multiple facilities."

Tagging along

At Ford Motor Co., WhereNet has set up a wireless parts-replenishment system that automates the parts-replacement function. The material call system is a real-time locating system based on a network of readers and wireless tags. Readers locate and track tags attached to supplies, providing a database of information that supports supply-chain visibility applications. Production workers submit parts requests for delivery to their work- stations by simply triggering a button on the WhereNet call tag.

Turner says the application also fits numerous warehouse uses, including those that store goods with a limited shelf life, such as beverages. "We can set alerts that tell the manufacturer the trailer has been on the lot for 48 hours, and it's time to get it off to market. Otherwise there may be a spoilage problem."