When General Motors Co. (IW 500/4) first considered producing the Chevrolet Sonic at its assembly plant in Lake Orion, Mich., the automaker saw a facility that represented "everything that we thought was good in General Motors," recalled Scott Whybrew, GM's top manufacturing engineering executive.

The 4.3 million-square-foot plant boasted an army of robots, "the latest and greatest" conveyor system and the muscle to run 72 jobs per hour, said Whybrew, executive director of global manufacturing engineering for GM.

"The issue that we had was that to build a subcompact car, we had to cut our investment level and really go back to basics with the simplistic tooling concepts that we've used at other spots in the world to be competitive," Whybrew told attendees of the Center for Automotive Research's Management Briefing Seminars in Traverse City, Mich.

"And now we're using the Sonic in Orion to be able to learn in manufacturing engineering to really simplify."

For example, instead of an overhead conveyor system, the plant uses automated guided carts on the floor to deliver parts and materials.

GM designed the carts to "accommodate multiple vehicle styles in sequence as well as flexibility for future models," Whybrew noted.

"Automated guided carts -- very simple," Whybrew said. "The operator can actually take and change out the battery, so we need no skilled tradesmen in order to keep this conveyance system working."

A geo-pallet system in the body shop has replaced the traditional underbody conveyor line.

"It allows us to exchange that pallet off of the weld line, and it allows us to build multi-platforms through the same operation and on the same line," Whybrew said. "Our geo-pallet approach helped us reduce our investment and overall operating cost."

Meanwhile, through the use of high-density welding cells, the Orion plant has shrunk its body-shop footprint by one-third.

"And that reduces our investment and the number of stations that we have to maintain," Whybrew added.