Collaborative product development in CAD and CAPP, an approach based on communication due to constraint conflicts and user initiative

This paper addresses collaborative product development, focusing on computer support of collaboration between users of CAD systems alone, between users of CAPP systems alone and between users of both CAD and CAPP systems. Computer support of collaborative product development may enhance informal information exchange. Apart from formal information exchange between CAD and CAPP systems, informal information exchange is necessary in achieving the goals of Concurrent Engineering. Collaboration can be started in a number of ways; as a result of one or more conflicts in constraints belonging to several users or voluntarily on the initiative of a user. Both these ways of starting collaboration should be supported. Besides collaboration, important related issues are engineering data management, handling of multiple views, design histories and a facility of supporting project management. A prototype implementation restricted to a re--design support oriented CAD system supporting both conflict based and voluntary communication is presented. The re-design support system currently supports several constraint types. The present implementation uses parameter constraints in the support of conflict based communication. A parameter constraint solver based on the use of simulated annealing is employed