Process query language: A way to make workflow processes more flexible

Abstract

Many requirements for a business process depend on the workflow execution data that includes common data for all the population of processes, state of resources, state of processes, etc. The natural way to specify and implement such requirements is to put them into the process definition. In order to do it, we need: (1) a generalised workflow metamodel that includes data on the workflow environment, process definitions, and process execution; (2) a powerful and flexible query language addressing the metamodel; (3) integration of a query language with a business process definition language. In this paper the mentioned workflow metamodel together with the business process query language BPQL is presented. BPQL is integrated with the XML Process Definition Language (XPDL) increasing significantly its expressiveness and flexibility. We also present practical results for application of the proposed language in the OfficeObjects* WorkFlow system. © Springer-Verlag Berlin Heidelberg 2004.