According to market research firm Daratech (www.daratech.com), 80% of product costs are incurred during the first 20% of the design and development process. And that's the reason Daratech recommends use of simulation technologies to avoid unnecessary design rework and costly physical prototypes. The company says that Ford Motor Co., Visteon Corp., and Goodrich Aerospace use computer-aided engineering early in the design process to enable more successful, efficient, and cost-effective product development. They use simulation to replicate the behavior of aircraft braking systems, for example, and to create abstract simulation and product models that remain valid regardless of geometric variations within the product.