manufacture has significantly reduced the time and costs of retooling manufacturing equipment. Virtual manufacturing pulls all of these technologies together into an agile manufacturing enterprise, a virtual factory on a computer that can analyze and pinpoint flaws in the manufacturing process before they occur on the factory floor.
OEMs in integrated supply chains are increasingly asking suppliers to become more involved in all phases of the product realization process. In a similar manner, SMEs should involve their customers and suppliers in the design process. In many cases, involvement in the design process is a new role for SMEs, offering them opportunities to add substantial value to the capabilities they already provide and linking them more closely with the OEM. Early participation by suppliers can enable better designs for manufacturability, provide better opportunities for implementation of advanced materials and processes, and provide sufficient time for the simplification of tooling. Many SMEs have had to expand their design capabilities to participate. For example, GM recently announced that the new Chevrolet Silverado pickup truck was built without traditional clay or wood models. The truck was designed on workstations with engineering software that enabled vehicle, parts, die, and plant designers to work simultaneously on the new product. Suppliers needed enhanced modeling and simulation capabilities to participate (Manufacturing Engineering, 1999).
Led by the automotive, aerospace, and defense industries, what began 20 years ago as CAD and CAM has expanded into highly complex modeling and simulation capabilities that use interactive design and development tools to reduce the costs and time required for product development and realization. The U.S. Department of Defense is beginning a major initiative called Simulation-Based Acquisition (SBA), the objective of which is complete modeling and simulation of all major weapons systems prior to manufacturing. Simulation-based design, a segment of SBA, uses a digital knowledge environment to represent physical, mechanical, and operational characteristics of these complex systems. In addition to electronically integrating product and process development, prototypes can be tested in virtual environments prior to fabrication. In response to this initiative, prime contractors are increasingly using these advanced technologies and, to the extent that their supply chains are integrated, they will increasingly expect these capabilities from suppliers. When fully implemented, SBA will go far beyond design, modeling all aspects of the product life cycle, from initial concept through manufacturing, sustainment, and even disposal or recycling.