Test Result Analysis with Respect to Formal Specifications

There are two aspects to testing: (1) the selection of appropriate test inputs and (2) the analysis of the observed interactions of the implementation under test (IUT) in order to determine whether they conform to the IUT's specification. The paper considers the second aspect with particular attention to the testing of OSI communication protocol implementations. A system is described which analyses an observed test trace of interactions with respect to a reference specification which is assumed to be written in LOTOS. In the case that an error is detected, the system also provides some diagnostic information for locating the "error" in the analyzed trace. The practical use of such a trace analysis system is discussed, as well as the possibility of using a similar approach for the validation of the verdicts which are included in the standardized OSI conformance test cases.