Design of the Test Description Language (TDL) (STF 454)

There has always been a methodology gap between the simple expression of what needs to be tested i.e., the test purposes described in prose or TPLan and the complex coding of the executable tests in TTCN-3. TDL covers that gap. Dedicated test descriptions will have a positive impact on the quality of the tests through better design and by making them easier to review by non-testing experts. This will improve the general productivity of test development. It opens the door to a new generation of programmers looking to a faster test development process without sacrificing quality. This approach is driven by industry to foster the benefits of model-based software engineering at the testing side. TDL is planned to fit into the ETSI test specification development process and is the second (and currently missing) step in a potentially seamless test development methodology. TDL introduces modelling techniques (with graphical and textual syntax) to the specification of test descriptions for testing communicating, reactive real-time systems. Many of them are designed and standardized by ETSI, e.g., Long Term Evolution (LTE), IP Multimedia Subsystem (IMS, TISPAN) and Intelligent Transportation Systems (ITS). However, the scope of TDL goes beyond "typical" communicating systems. It will also support the description of tests in other domains that do not necessarily rely entirely on message-passing communication interfaces. With the advent of new software engineering technologies supporting the design of languages with multiple syntaxes the realization of TDL becomes a feasible task. Furthermore, TDL can be used as an intermediate representation of tests generated from other sources, e.g. simulators, test case generators, or logs from existing test runs. TDL therefore contributes to the ongoing activities in TC MTS to establish model-based testing (MBT) technologies within ETSI that are expressed, for example, in the ETSI standard on requirements on MBT notations (ES 202 951).