Conformance Checking in Integration Testing of Time-constrained Distributed Systems based on UML Sequence Diagrams

The provisioning of a growing number of services depends on the proper interoperation of multiple products, forming a new distributed system, often subject to timing requirements. To ensure the interoperability and timely behavior of this new distributed system, it is important to conduct integration tests that verify the interactions with the environment and between the system components. Integration test scenarios for that purpose may be conveniently specified by means of UML sequence diagrams (SDs) enriched with time constraints. The automation of such integration tests requires that test components are also distributed, with a local tester deployed close to each system component, coordinated by a central tester. The distributed observation of execution events, combined with the impossibility to ensure clock synchronization in a distributed system, poses special challenges for checking the conformance of the observed execution traces against the specification, possibly yielding inconclusive verdicts. Hence, in this paper we investigate decision procedures and criteria to check the conformance of observed execution traces against a specification set by a UML SD enriched with time constraints. The procedures and criteria are specified in a formal language that allows executing and validating the specification. Examples are presented to illustrate the approach.