In almost 10 years of trying, the industry has yet to prove that the so-called "plant of the future" has a future.
The Chrysler group's Jeep plant in Toledo, Ohio, is the latest effort to integrate suppliers into assembly and have them absorb some of the financial risk.
A handful of these factories have opened with much fanfare in the past decade. But none is held up as a shining example of how to build cars efficiently.
"I don't think I'd stand back and say any one of them is the model yet," says Ronald Harbour, president of Harbour Consulting and a principal author of The Harbour Report, which annually measures North American auto plant productivity.
Volkswagen AG, Ford Motor Co., and General Motors all have plants in Brazil with varying levels of supplier investment and assembly line involvement.
DaimlerChrysler also had one in Brazil. Dana Corp. supplied a rolling chassis to DaimlerChrysler's Dodge Dakota pickup plant in Campo Largo, Brazil, for 19 months. The automaker closed the plant in early 2001, the victim of a faltering Brazilian economy.
It's tough to draw conclusions about these plants because they are experimental, Harbour says. But he wonders if these moves are designed to get around the lack of flexibility in most assembly plants.
"Is this really just a flexibility issue?" Harbour asks. "Do we pawn off the smaller volume stuff because we don't have plants that are flexible enough?"
The biggest example of suppliers in assembly plants is DaimlerChrysler's Smart plant in Hambach, France. Smart is a unit of DaimlerChrysler's Mercedes Car Group.
Smart puts suppliers inside the Hambach plant to integrate them into core assembly.
The plant, called Smartville, opened in 1998 with one model - the City Coupe, now called the ForTwo. Today the plant produces four models. The suppliers construct their modules in the plant and supply them directly to the production line. This reduces inventory to almost zero.
"There's always a risk any time you delegate any portion of an operation to another party," says Catherine Madden, production analyst at Global Insight Inc., in Waltham, Mass. "But I think the OEMs want it to be the wave of the future. DaimlerChrysler is taking the first, biggest, most noticeable step."
A key to success in the Toledo plant will be the relationship that the automaker has with the suppliers, Madden says.
"An excellent relationship is a must," she says. "You've got to be able to work together. Without that I think the whole thing would fall apart. That puts a lot of pressure on them."