PDM procedure management supporting concurrent engineering

In the first section, this paper firstly introduces the product data management, then analyzes the traditional design procedure and describes the design procedure supporting concurrent engineering, furthermore it brings forward to two concurrence styles. intraprocedure communication and interprocedure communication. In the second section, this paper implements the intraprocedure communication using snapshot method, then gives the data structure of procedure and puts forward to the step state conception, furthermore defines the finite state machine of step and describes the semicommit and rollback algorithms. In the third section this paper introduces the message passing mechanism to supporting the interprocedure communication, then advances a new theory to detect the deadlock between the procedure based on the BeforeSet, furthermore it gives the detailed algorithm and a trace result of an example. In the last section, this paper gives the architecture of procedure management software.