Accurate and timely communication is critical in today's design and manufacturing environment. For products such as automobiles, aircraft, missiles, and similarly complex items, many individuals and specialties are involved in the development effort. Some may be geographically separated from others. Without good communications among these people and with the customer, requirements can be overlooked. Communications are enhanced through the use of computer-aided design and manufacturing (CAD/CAM) and the use of common data bases.