The need for concurrency in design and manufacturing is supported in a recently developed sheet metal design system by doing preliminary process design at the detail product stage. This new ``design with features'' approach represents the evolving part form to the designer in multiple process domains and at multiple stages of a sequential process. Each pair part form representations defines the conceptualized process which transforms it from one to the other. At the modeling level, processes are reversible so that design activity can take place in any of the domains and transfer to others. We have fully implemented this concept in a sheet metal design/manufacturing system in which preliminary process design occurs concurrently with product design and the normal representation ambiguities of wireframe and flat panel models are eliminated.

C.-H. Wang and R.H. Sturges, ``Concurrent Product/Process Design with Multiple Representations of Parts,'' in Proc. IEEE. Int. Conf. on Robotics and Automation, Vol. 3, pp.298-304, 1993.