Changing a die design for a body panel stamping is difficult, expensive and an unfortunate way of life for some automakers.

Unigraphics Solutions has an answer with its latest technology, Smart Model. The St. Louis-based company is the primary supplier of computer-aided design and computer-aided manufacturing tools (CAD/CAM) to the world's largest automaker, General Motors Corp., and the world's largest supplier, Delphi Automotive Systems.

Recently, GM began using Smart Model, which is an extension of Unigraphics' UG/Wave, a software package introduced a few years ago that is similar to parametric modeling, allowing assembly-wide changes to be driven by product dimensions and engineering parameters.

In its initial application, GM is using Smart Model to produce dies for body panel stampings, a process that used to take five to eight weeks and now can be completed in a matter of minutes. In the past, whenever changes were made to the body geometry, engineers had to manually redesign the dies.

But UG/Wave establishes a relationship between the body geometry and the die design. All the engineer needs is a preliminary design - or even a design of a similar stamping from a different vehicle - which can then be "morphed" to meet the final design parameters.

The system is a natural evolution for CAD systems, which have advanced well beyond being mere electronic drafting boards.

"CAD systems have progressed from the beginning when they had no intelligence to now being able to capture almost anything you want. You're not just drawing lines - you're capturing valuable information," says Gary Pomerantz, engineering manager at Unigraphics.

"We've enabled it so a designer can program his part pretty much the way a software programmer would program a custom application," Mr. Pomerantz says. "We can tell a CAD system what to do based on a given input. Before, you had to manually redraw your die model. Now, we've embedded enough intelligence in the model to figure out most things for itself."

Smart Model should streamline product development by altering the sequential nature of body panel design: Die engineers usually wait for body geometry to be frozen before starting their work, which must be completed before die designers can do their jobs. A late change in body geometry sends everyone back to square one, besides being enormously expensive and wasteful.

Rather than waiting for final parameters, Smart Model allows die designers to start working immediately on preliminary geometry while die engineering is under way. When the body geometry changes, the die assembly model updates automatically.

Unigraphics demonstrates its Smart Model technology during the recent dedication of its new Innovation Center in Livonia, MI. The center features an 8- by 20-ft. (2.4- by 6.1-m) Immersive Visualization PowerWall (courtesy of Hewlett-Packard Co.), allowing employees and customers to put on 3D specs and address design issues in human scale, rather than on a tiny computer screen.

While GM initially is using Smart Model for body stamping dies, Unigraphics says the system can be used any time a basic assembly must be adapted to multiple geometries within a family of parts.

GM isn't saying how soon a vehicle body will be produced using Smart Model, but the company is beginning to apply it on current work, says Darryl Syms, supervisor for computer-aided die systems at GM.

The system also will make die designers more efficient but shouldn't lead to any employee cuts, Mr. Syms says. "This is like what happened with word processing," he says. "We're taking people and increasing their level of skill and understanding. The die designers are enthusiastic about it."

But if concerns do arise about staff cuts, GM could contend that a lot of die work is already outsourced to job shops, and now that work can be moved in-house, preserving jobs.

Besides, GM needs people to launch a raft of new vehicles. The company has aggressive plans to begin selling a new, redesigned or moderately tweaked vehicle every 28 days worldwide until at least 2005. In North America alone in 1999, GM is launching 14 new vehicles.

If Smart Model takes off in popularity, Unigraphics should be able to sell more CAD stations, because the system is compatible only with Unigraphics software. Part files, however, can be imported into Smart Model from other CAD systems. Unigraphics says several automakers and suppliers currently are reviewing the product.