Lear Seating, like so many other automotive suppliers, fell on hard times during the recent recession … but it wasn’t because of a lack of innovation or quality. This system that Integrated Systems Design developed and installed in their Montgomery, Alabama plant helped them win Assembly Magazine’s prestigious Assembly Plant of the Year Award in 2006. See what makes this plant and system stand above others.
Lear Assembly Plant Drives for Perfect Delivery & Quality Assurance
Lear Corporation’s 94,000 square foot, four assembly line seating plant in Montgomery, Alabama is one of the most modern and efficient facilities of its kind, and received the prestigious Assembly Plant of the Year award from Assembly Magazine.
At peak production, Lear builds approximately 1,000 seat sets per day or 73 sets per hour in 56 distinct combinations of colors and options for the Hyundai Sonata sedan and Santa Fe SUV built at Hyundai’s Alabama plant. The seats are assembled on pallets with fixtures that can rotate and tilt for worker accessibility, providing an ergonomically sound procedure that improves efficiency. The assembly lines use a non-synchronous looping conveyor system, with an automated, timed-release at each workstation that can be overridden by the operator when necessary.
The focus is on Just-In-Time (JIT) delivery. The Lear plant receives an estimate each day of which seat models will need to be built for Hyundai’s scheduled production. About two hours before the seats need to be installed into the cars, Lear receives a live broadcast of the exact production sequence and seat model requirements from Hyundai.
Assuring Quality Assembly
The entire assembly process is managed by an Integrated Systems Design PC-based quality assurance system that improves overall seat quality by monitoring the seat assembly and sequencing process. The quality assurance system is interlocked to the Integrated Systems Design conveyor system to prevent seat movement before each assembly and inspection step is properly completed at a particular workstation.
Read-only RFID tags on each build fixture are “married” to each seat assembly at the beginning of the build process. RFID antennas located at each quality assurance station read the RFID chips embedded in the build pallets. The quality assurance system electronically displays instructions at critical workstations, working in conjunction with the RFID system, to provide positive seat identification and data tracking. Once a “work complete” message appears on the workstation display screen, operators can release the part they’re working on and allow it to move to the next process.
The system allows Lear operators to simultaneously assemble several different types of seats on the same production line. Build sequence numbers and specific work instructions for each seat are displayed at the assembly line workstations. Critical data, such as fastener torque and angle, are recorded and associated with each seat build sequence number and maintained for years, along with each seat’s build record/birth certificate.
Tracking Quality & Delivery
As the seats move down the assembly conveyors, the quality assurance system receives various tool, equipment and operator inputs and determines whether a seat assembly or component is a “pass” or “fail.” This information is used to route defective seats to a repair station, provide notification of the defects found, identify the operation that caused the defect and provide a means for tracking internal defects. The quality assurance system automatically sends information to Lear’s ERP system at several points in the assembly process. That information is used to trigger other events in the system and transfer data associated with each seat.
After a set of seats is assembled and placed on a shipping pallet at the Lear plant, they’re wrapped in a plastic bag and bar code labeled. The seats are then transferred to the shipping area and prepared for delivery to the customer. An Integrated Systems Design UltraStore mid-load automated storage and retrieval system (ASRS) determines where to store the seats based on the bar code. The system also selects and retrieves seats in the order they are to be shipped, based upon the live broadcast from the Hyundai plant.
Because the seats are moved exclusively by an automated system from Hyundai’s receiving dock to the assembly line, Lear software directs the ASRS to sequence each truck load of seat sets in reverse broadcast order prior to loading. This ensures that they’ll be delivered in the correct sequence to the assembly line precisely when the appropriate vehicle reaches the seat install location.
Passive read-write RFID tags are also used in the outbound shipping sequence control system. A chip is mounted to the rear of each of Lear’s fleet of conveyorized semi-trailers. RFID antennas are located on Lear’s shipping dock and Hyundai’s receiving dock. Each semitrailer holds 54 seat pallets, which are automatically loaded onto a truck in less than one minute by an Integrated Systems Design shipping conveyor system. When a truck is loaded, trailer sequence information is written to the trailer’s RFID chip. The chip’s information is then checked to ensure that the write was successful. The sequence control system won’t allow the trailer’s dock lock to be unlocked unless the correct data has been written successfully to the chip.
When the trailer is backed into Hyundai’s dock, the RF chip on the semitrailer is read. If the trailer sequence information is correct, the Hyundai conveyor control system allows workers to initiate the trailer unload sequence. If the trailer sequence information is incorrect, an alarm horn and beacon are activated, and Hyundai employees are prevented from unloading the truck until the correct trailer is in place at the dock.
Handling Return Pallets
The pallets that the seats are shipped on to Hyundai return to the Lear facility in stacks on the same dedicated Integrated Systems Design conveyorized delivery trailers. The driver connects the trailer conveyor to Lear’s in-plant conveyor system via an umbilical cable plugged into a receptacle adjacent to the exterior dock door. He then initiates the trailer unload cycle. The stacks of empty pallets are automatically conveyed to an Integrated Systems Design installed mezzanine level where they’re staged until needed.
Lear prides itself on achieving 100 percent on-time delivery to the Hyundai plant. The Integrated Systems Design material handling equipment and quality assurance system are an integral part of ensuring they maintain their record .