Process Synchronization In Workflow Management Systems

Workkow Management Systems (WFMSs) automate the execution of business processes allowing the concurrent execution of multiple process instances. Existing systems do not provide a mechanism to guarantee correct concurrent execution and, as a result, it is not possible to coordinate and synchronize diierent process instances. Part of the problem is that conventional techniques are not entirely suitable for workkow environments. In databases, locks are the basic mechanism. In operating systems, the same is achieved using semaphores or monitors. Neither of these approaches is appropriate for workkow applications. In this paper a method is proposed to enforce correct interleavings and guarantee mutual exclusion, as deened by the user, between concurrent workkow processes. The proposed protocol takes advantage of the semantic constructs associated to workkow management to solve some complex problems such as dealing with inherited restrictions and the coarse granularity of workkow speciica-tions.