Workflow modelling using a temporal object-oriented model with roles

Abstract

The representation of all the processes that compose a workflow, including all the constituent activities, their execution sequence and relationships, the agents responsible for their execution, and the resources that are used during execution, is known as Workflow Modelling. Several techniques are being proposed to model workflow. In this paper a workflow modelling technique is proposed, using a temporal object-oriented data model, the TF-ORM model. The TF-ORM model is presented, as are the extensions made to adequate the model to workflow modelling. All the activities that shall be executed during the workflow are represented, including the mechanisms for their activation and termination, both in normal and exception situations. The model allows the representation of structured and unstructured work, the interactions that will occur among executing activities, and their synchronization. The workflow model represented in TF-ORM includes a set of rules to be used during the workflow management. The occurrence of failures and exceptions during workflow executionmay cause serious problems, especially in mission-critical applications. The TF-ORM formalism, when used to model workflow, allows the representation of several exceptions and the definition of information to be used for the systems recovery.