Writing Test Cases (or TCs) is one of the final steps in the development of a complete test specification. Each TC is an executable test script or program that can be compiled and run on a suitable test system.

The TCs are based on the Test Purposes (or TPs) identified in the relevant standard (or standards) from which the test specification is derived. The entire set of TCs is called a Test Suite (TS).

Nearly all ETSI Test Suites are written in the Testing and Test Control Notation (TTCN). TTCN-3 is developed and maintained by ETSI TC MTS as the ES 201 873 series and by the ITU-T as ITU Recommendation Z.16x series.

Although primarily used in telecommunications, TTCN is well accepted by industry and its use has spread into new domains including automotive, railway and financial applications. Typical areas of application for TTCN-3 are protocols, services, APIs (Application Programming Interfaces), and software modules. However it is not restricted to conformance testing and can be used in areas such as:

Benefits of using TTCN-3

For more information see