Requirements monitoring for service-based systems: towards a framework based on event calculus

This work proposes a framework for run-time monitoring of the compliance of systems composed of Web-services with requirements set for them. The framework assumes systems composed of Web-services which are coordinated by a service composition process expressed in BPEL4WS and uses event calculus to specify the requirements to be monitored. These requirements include behavioural properties of the system which are automatically extracted from the specification of its composition process in BPEL4WS and/or assumptions that system providers can specify in terms of events extracted from this specification. Requirements are checked using a variant of techniques for checking integrity constraints against temporal deductive databases.