Digital Prototypes? Sometimes, “Going Back to Basics” is Better

It’s easy to fall into the trap of relying too much on digital prototyping to test products. So says Brian R. Lyons, safety and quality communication Manager at Toyota Motor Sales U.S.A. Inc., Torrance, Calif. “For many years, Toyota has practiced a disciplined and metered method to manufacture vehicles. It lets the company build high-quality cars,” he says. “The approach included several prototypes for each model, obviously an expensive proposition. To cut costs, we increased our use of CAE and built fewer prototype vehicles.”

This helped reduce costs by letting engineers compare aerodynamic flows in different simulated engines rather than actually building physical engines. However, the company suddenly saw an increase in quality issues.

“We started seeing problems we never had before,” says Lyons. “For example, we extended the warranty on the 2001 through 2003 Prius because a ‘check-engine’ light kept going on. We had done extensive digital testing on the engine and its components, and everything worked fine in the virtual world for hundreds of thousands of miles. But after the cars had been in operation for several years, it became evident that certain fuels used in the U.S. leave carbon deposits on the throttle body. Digital testing didn’t match real-world roads and environmental conditions in the U.S.,” he says.

So the company decided to keep using CAE but also go “back to basics,” using what worked in the past. The approach is summed in the idea of “genchi genbutsu,” or “go and see,” says Lyons. “In other words, we ramped back up on physical prototyping. When the Highlander came out, we launched our Customer First initiative. As part of this, we increased the number of physical evaluations letting quality assurance, product planning, and even sales and marketing personnel test drive cars in real-world conditions. The Highlander was the most problem-free car we launched at the time. Now we’ve produced several models using this approach.”

The back-to-basics approach continues to lower warranty numbers, says Lyons. It also lets Toyota build cars that better target different markets. “We had to find out how consumers in different areas of the world actually drive the vehicles,” he says. “For example, unlike Japan, it’s common in the U.S. to drive on gravel and dirt roads. There is less traffic here than in Japan, and roads are wider with a lot of high-speed driving. Canadian and European drivers are different as well. In Europe, for example, you find extremely bumpy Belgium block roads made of slabs of rock and mortar.”