Real-Time Inventory Tracking
WhereNet's WhereCall/Fast Gate RFID Systems

As companies implement lean manufacturing processes, it's important to have real-time information. Knowing what you've got and where it is at any given time in the supply chain should be straightforward. Multiply that simple task by an enormous business with tens of thousands of items, such as Ford Motor Co., and knowing what you have—and where—becomes staggeringly complex.

Ford's manufacturing operations depend upon having the correct amount and type of production line-side inventory on hand at all times. Lacking adequate visibility into the location of containers, the company faced challenges of excess line-side freight, lost production capacity and inventory obsolescence.

To meet these challenges, Ford adopted an active radio frequency identification (RFID) real-time locating system, which has been implemented in almost all of its North American and European plants. The system, from WhereNet Corp. of Santa Clara, California, is driven by wireless tags, fixed-position antennas and Web-enabled software. This industrial information system locates and tracks inventory using extremely low-power radio frequency tags and a communications network. Antennas positioned inside and outside the factory receive tag transmissions and deliver tracking information to a computer. The system then locates the tag within 10 feet of its position.

Ford initially implemented its Where-Net system in February 1998, using it to track materials within a 250,000-square-foot area of its Van Dyke facility in Sterling Heights, Michigan, which produces more than 9 million components annually. Using the same local infrastructure of antennas, Ford and WhereNet then codeveloped a wireless "call" system (known as WhereCall) to bring parts to the line as needed.

When supply of a specific part reaches a predetermined replenishment level, the line worker presses the WhereCall button sending a signal to restock that particular part. This process eliminates the need for replenishment workers to pick up kanban cards. The system also eliminates some lag time from the process, further minimizing line-side inventories.

Using antennas mounted in the plant ceiling that pick up the "blinks" from the WhereTags, WhereCall's message for parts is conveyed to the WhereNet server, which determines the location of the call and the part to be replenished. The data is then passed on to Ford's SMART System, which in turn displays a message on a touch-screen computer.

Most recently, Ford implemented another application of WhereNet's real-time locating technology at its Oakville Assembly Complex in Ontario, Canada. By expediting delivery of just-in-time parts, WhereNet's automated "Fast Gate" check in/out solution has dramatically improved the efficiency of Oakville's freight and inventory management system.

The WhereNet deployment was part of a transformation of the Oakville complex to flexible manufacturing, allowing for quick responses to market demand without the lengthy, expensive retooling process required for traditional model changeovers. With flexible manufacturing, inbound parts shipments from suppliers are smaller and more frequent—in Oakville's case, hundreds of daily truckloads of thousands of components in sequence. By automating the check in/out procedures, the WhereNet system saves Ford several hours a day processing deliveries, and increases efficiency in the supply chain.

The WhereNet Fast Gate system puts a "wireless cloud" over the entire Oakville complex with active RFID WhereTag transmitters permanently fixed to trailers belonging to Ford's dedicated suppliers (and temporarily fixed to others), 14 WherePort magnetic "exciters" positioned at each gate, and a local infrastructure of 69 wireless WhereLAN access points throughout the complex.

When a truck approaches a gate, the WhereNet Fast Gate system senses the WhereTag, cross-references detailed information about a truck in a database and automatically opens the gate to grant entry if the truck and its load are authorized. The driver then drops the trailer at any one of 177 receiving dock doors and departs via a similar automated checkout procedure without ever leaving the cab. Meanwhile, the WhereNet system captures the location of each trailer and precise information about its cargo, and wirelessly transmits that information to a database.

"The WhereNet system gives Ford the agility to manage its inbound supply chain on a minute-by-minute basis to support flexible manufacturing processes and rapidly adjust to shifting market demands," explains Tom Bacon, vice president of WhereNet's automotive division. "Our active RFID rules-based yard management system allows Ford to efficiently track the movement of about 1,000 trucks a day, ensuring that each of the 2,000 parts needed to build every vehicle is delivered to the assembly line at the precise moment it's needed."

WhereNet's WhereCall/Fast Gate RFID Systems

Benefits:

• WhereCall simplifies replenishment and eliminates the need for kanban cards
• It eliminates lag time, further minimizing line-side inventories
• Fast Gate automates the tracking of supplier deliveries, saving several hours of processing time each day

www.wherenet.com