Quality matters: Systems Quality & TTCN3
The quality of software-based systems becomes increasingly important as the influence of software in almost every area of economy and society is growing. Today, software is used in safety-, security- and business-critical domains for systems where reliability, robustness, trustworthiness, etc. are essential.
Analytical methods and in particular dynamic testing approaches remain a central and often also exclusive instrument to check the resulting quality of the overall system. For years, experts have been convinced that test design is the central element to successful and meaningful software testing. In the meantime, however, it has become apparent that testing requires all the typical elements of software engineering: tests are software-based systems themselves and need to be engineered, designed, verified, validated, and executed like any other software-based system. Specialities of test systems involve the ability to control, stimulate, observe, and evaluate the system under test. Although standard development and programming techniques are mostly applicable, specific solutions for the development of test systems respecting their peculiarities seem reasonable. This motivated the development and standardisation of specialised test specification and test implementation languages.
Among the original reasons for developing the Tree and Tabular Combined Notation (TTCN) was the precise definition of conformance for protocols of telecommunication components according to their specifications. Test specifications were regarded as means to objectively define test procedures and to evaluate, compare, and certify equipment on a sound and repeatable base. In the spirit of these developments, the automated execution of TTCN became likewise important.
Over the years, TTCN grew in its expressivity and usage. Various pilot projects demonstrated its successful applicability outside the telecommunication area. With the convergence of the information technology and telecommunication industries, the direct applicability of TTCN became also apparent to people without a background in the telecommunication domain. These trends and the characteristics of more recent IT and telecommunication technologies imposed new requirements on TTCN itself. The development of a new version of TTCN – TTCN-3, now standing for Testing and Test Control Notation version 3 – is the result of these new requirements.
TTCN-3 has been developed by a group of testing experts at the European Telecommunication Standards Institute (ETSI). Launched in September 2000 as a new standardised test technology, it is since then continuously maintained and improved along the needs of its user community.
Fraunhofer FOKUS is main contributor to TTCN-3 and is responsible for various elements of the language definition including part 1 (concepts and core language), part 5 (runtime interfaces) and part 6 (test control interfaces).
You may find a compact overview of the TTCN-3 language elements in the TTCN-3 Quick reference card.