tion testing method with an architectural test coverage criteria. This method is suitable for systems that lack system documenta- tion and is applicable during regression testing and deployment phase. This paper also presents the initial results of an empirical study that validates the proposed test coverage criteria against an existing method in terms of the test coverage using a test suite precision parameter. We also describe the test models used that are based on probabilistic deterministic finite automata which are used to represent gate usage profiles at run-time and test execution. These models facilitate the representation and validation of the gate protocol, test coverage measurement and monitoring of the test suite coverage of each gate.