A blond woman in pigtails walks down the sidewalk barefoot with a green tube on her back.
The woman walks down on the street.
Commercial companies demand knowledge from virtual or engineering prototypes, 90 percent of required engineering drawings for the product supported by test results, demonstration that the product meets customer requirements, a series of disciplined design reviews, and stakeholder agreement that the design is stable and ready for product demonstration before a commitment is made to move forward and invest in product demonstration.