Using the guard-stage-milestone notation for monitoring BPMN-based processes

Business processes are usually designed by means of imperative languages to model the acceptable execution of the activities performed within a system or an organization. At the same time, declarative languages are better suited to check the conformance of the states and transitions of the modeled process with respect to its actual execution. To avoid defining models twice from scratch to cope with both the process enactment and its monitoring, this paper proposes an approach for translating BPMN process models to E-GSM ones: an extension of the Guard-Stage-Milestone artifact-centric notation. The paper also shows how a monitoring engine based on E-GSM specifications can detect anomalies during the execution of the process and classify them according to different levels of severity, that is, with respect to the impact on the outcome of the process.