HyperMSCs and Sequence Diagrams for use case modelling and testing

UML-Sequence Diagrams can be seen as an object oriented variant of the ITU-T standard language Message Sequence Chart (MSC) which is very popular mainly in the telecommunication area. Both notations would benefit from a unification together with a further elaboration. A comparison of Sequence Diagrams and MSCs demonstrates the big advantage of MSCs concerning composition mechanisms, particularly with respect to the branching construct in Sequence Diagrams. Therefore, MSC inline expressions and High Level MSCs (HMSCs) are of special interest for the inclusion into Sequence Diagrams. High Level MSCs may be employed for formalizing and structuring the construction of scenarios for Use Cases. In order to arrive at a most intuitive representation, HMSCs are re-interpreted in a way which has an analogy in hypertext-like specifications. Because of this analogy, the notation 'HyperMSC' is introduced. The scenarios derived from Use Cases in form of HyperMSCs can be employed also as a basis for the specification of test cases.