"Our whole culture is now based on understanding that it's all about continuous improvement." That sweeping statement is Pam Mader's introduction to GM's Moraine Assembly Plant (Moraine, OH), where she is plant manager. She is able to make it so boldly because in preparation for the launch of GM's new mid-sized SUVs a year ago, Moraine was largely gutted and rebuilt. The processes and practices at the plant are consequently based on the General Motors Global Manufacturing System (GMS), which is a holistic approach to vehicle manufacturing similar to the Toyota Production System. It employs error-proofing, problem-solving, standardized work and worker empowerment to raise quality and cut costs, and its application has completely transformed the way Moraine builds vehicles.
GMS emphasizes teaching people how to catch and solve problems. It also uses a lot of computer power to make sure things go right. The Common Operator Support System (COS) used at Moraine monitors the andon, error-proofing, and electronic material pull systems and ties that information into the Common Quality Information System (CQIS). CQIS shows real-time production data, including where and when defects are occurring. It can be accessed from any computer in the plant simply by clicking on a desktop icon. All of GM's plants now use CQIS, so production managers can not only check to see where defects are most prevalent in their own shops, but can compare with other plants that build the same products. Moraine had a far less-sophisticated computer system in the past that could not track problems down to a component or operator level. Now that CQIS has made that possible, officials say that quality has improved and off-line repair has been greatly reduced.
A typical chassis assembly station provides a good illustration of the number of computer-generated checks that are applied to each vehicle. As a carrier enters the station, a bar code scanner is activated that reads the Primary Vehicle Identifier (PVI) code on the bottom of each frame. If the PVI matches what has previously been entered into the system, stack lights flash green and information is fed to tracking zones in the area to set error-proofing functions. Workers in each station must perform error-proofing tasks like shooting bolts to a given torque or hand scanning parts to ensure they are correct for the vehicle being assembled. If this activity is not completed by the time the body gets approximately three-quarters of the way through the station, the computer causes the stack lights to flash yellow. This alerts both the operator and off-line managers that a potential problem is brewing. If the error-proofing is not finished by the time the body reaches the end of the station, the line stops until the task is done or the body is manually released. Any body released without receiving the prescribed procedure is tracked by the COS and not allowed to ship until all standards have been met.
To enhance efficiency, Moraine has resized areas in the plant. A more efficient ordering of processes allowed the plant to reduce the overall length of its chassis line by over 60%. Similarly, the trim shop was compressed by about 30%, even though Moraine's current products, the Trailblazer, Envoy and soon-to-be-defunct Bravada are much bigger than their predecessors. The weld department, on the other hand, has expanded dramatically.
Before being refurbished, Moraine had about 280 robots in its weld shop and received many of its major parts like doors, hoods, and liftgates directly from GM's fabrication plants. Now it boasts over 750 Fanuc (Rochester Hills, MI) robots that have given it the ability to build up its own components. Based on weld spots and panels, capacity has almost doubled. The weld shop's management team says that making the components in-house gives them greater control over dimensional accuracy, and that their proximity to the assembly line speeds problem feedback and countermeasures. It also reduces freight costs, since it is cheaper to ship in panels than whole assemblies, and allows the fabrication plants to concentrate on maximizing stamping output. Hard tooling has been eliminated in favor of the robots that Moraine officials say will give them the capability to make model changes faster and with little additional investment. When asked to characterize the difference between launching a new model under the old system and the new, Mader simply says, "Night and day."