NASHVILLE, April 10 -- General Motors' decision to ask owners not to drive its new mid-sized sport-utilities until they are repaired was not influenced by the troubles Ford Motor Co. experienced with the Firestone tire recall, the head of GM vehicle production says.
The control arm failures caught GM by surprise because the problem never occurred on test fleet vehicles that were driven more than 1 million miles, Briggs says. GM has shut down the Moraine, Ohio, assembly plant that builds the sport-utilities until revised parts are available.
Briggs would not place blame for the defect on either GM or the supplier of the part. "We know it didn't happen at the assembly plant, but it's premature to point the finger," he says. GM has identified the cause of the problem and is moving to get redesigned parts flowing to the assembly plant, Briggs notes.
The recall marred the launch of important vehicles for GM. The new sport-utilities are the product of some of the latest gains GM has made in its production system, Briggs notes, as well as going up against the redesigned 2002 Ford Explorer.
Briggs held up the Moraine plant as an example of the progress GM has made in implementing its Global Manufacturing System.
Using lessons learned from GM's partnerships with Toyota Motor Corp. at the New United Motor Manufacturing Inc. plant and Suzuki Motor Co. at CAMI Inc., as well as plant operations in Germany and South America, the Moraine plant was organized around small work teams. The manufacturing system also is influenced by lessons learned at Saturn Corp. Briggs was in charge of Saturn's manufacturing from 1985 to 1991. So the Moraine plant makes use of a height-adjustable, skillet-style assembly line similar to that used in Saturn's plant in Spring Hill, Tenn. It groups workers in small teams, with standardized work procedures targeted at meeting safety, quality, production and scrappage goals.
"The manufacturing system is built around people. Manufacturing is a people business," Briggs says.
Moraine also benefits from changes GM has made in its design and manufacturing engineering communities, Briggs notes. The automaker used the same computer-design data to design and produce the production tools as well as simulating and refining assembly line tools before any machinery was moved into the plant.
In order to make GM's manufacturing operations more flexible, all vehicles that share a platform must also share a common build sequence, with common interfaces and transfer points on the vehicle, Briggs says. Designers have wide latitude on items such as exterior panels — 70 percent of the sheet metal on the TrailBlazer, Envoy and Bravada is unique to each vehicle — but limited use of interchangeable modules in areas that consumers don't seek, he says.
Commonization stretches even to the assembly plant. Briggs noted that by commonizing the electrical architecture within an assembly plant, cost of the electrical system is reduced by 50 percent.
GM is implementing the new manufacturing system with every new plant it builds, such as the Grand River plant in Lansing, Mich., or with existing plants that get refurbished.
Says Briggs: "The challenge is to continually refine the system while still keeping it common."