Johnson Controls Inc., of Milwaukee, uses radio frequency identification (RFID) to help smooth out its assembly line. The company produces car and truck seats at its Livermore, Calif., plant. While car and truck seats have independent production lines, as the seats move to the inventory and packing stage of the plant, the two lines become one, mixing the car and truck seats together on the same conveyor. If the plant has an order of car and truck seats, customers request a specific order of loading, say, car, truck, car. If the seats are loaded on the trucks incorrectly, say, car, truck, truck, the production line comes to a standstill.
Plant managers turned to RFID to solve this persistent problem. “Our previous ID system involved basic clipboards and checklists located with operators at each station of production,” explains Fred Zaske, an electrical engineer at the Johnson Controls plant. “The main reason we invested in RFID was to eliminate human error that was prevalent with an operator.”
Plant managers at first sought a bar code system to solve the human errors. “We looked at a bar code system, but because of the dirty and often abrasive conditions of the production floor, we worried about bar codes getting dirtied or scraped, rendering them useless,” says Zaske. He notes that bar codes are also susceptible to misreads and would cost a great deal of time in troubleshooting on the line.
The company decided to implement an RFID system, which was installed by Escort Memory Systems (EMS), of Scotts Valley, Calif. Plant managers decided to extend the use of the RFID system to include recipe information on the seats as they moved down the production line. The tags contain recipe data that is picked up at each production station. Tag data tells the operator what operations need to be done to the seat. If nothing is required at a station, the tag tells the conveyor to keep moving.
As the seat moves down the line, operators make designated alterations and update the tag data. The process continues at each modification station until it reaches the final station where the seat’s recipe is verified. The seat then moves to the storage and shipping area where car seats and truck seats are aligned with customers’ orders. The system solves the original problem, while also improving the flexibility and accuracy of the entire assembly line.
See the story that goes with this sidebar: RFID Clocks In
