Improving the Quality of Test Suites for Conformance Tests by Using Message Sequence Charts

The test of a communication system is a complex procedure which comprises several phases with various tasks. The quality of a test depends on the work in the phases and an easy and smooth transition between the phases. In the current test practice the different phases are mainly based on informal documents and they do not always fit together properly. Therefore we intend to improve the phases and the transition between the phases. This paper shows how the use of Message Sequence Charts (MSCs) may improve the test specification phase and facilitate the transition to the test implementation phase. We describe the different phases of testing, sketch the problems of practical testing, and explain the use of MSCs for test specification by the example of an ISDN switching system. We show how MSC based test specifications can be transformed into executable test cases, and present a tool set which supports the test specification and automates the test implementation.