Architectures for a Temporal Workflow Management System

Workflows describe business processes as the coordinated execution of simple activities (tasks) by human or automatic executors (agents). Workflow management systems (WfMS) are software systems supporting the automatic execution of workflows. Most WfMSs rely on database management systems (DBMS) where temporal aspects, which are relevant for the execution of a workflow, are managed explicitly. In this paper we discuss different architectures for a temporal WfMS: then we propose yet another workflow system which novelly manages temporal aspects via a temporal database system, composed by a temporal layer on top of a relational DBMS (Oracle). The adoption of a temporal database system both benefitted the development of the engine and increased its efficiency by allowing some additional features, as the management of process model evolution and the selection of executing agents via a workload balance over time.