On the integration of design and test: a model-based approach for embedded systems

One of the most crucial questions concerned with model-based testing is how to find "interesting" test cases. We consider test cases to be interesting if firstly, they cover the user requirements and secondly, they have a high probability to find potential errors. In this paper we introduce an approach to derive test cases along different levels of abstraction during the design phase. These levels start with services representing user requirements on the topmost level and result in models for a specific technical platform on the most concrete level. Within the presented test process we use design models of different abstraction levels as test models out of which test cases can be generated. The test cases are executed on more concrete levels and finally on the implementation. An exception is the (topmost) service level which isused for the derivation of the test case specification.One main advantage of our approach lies in preserving the link from test cases to corresponding user requirements. Furthermore the danger of using too abstract models which do not reflect inevitable crucial aspects of the realization is avoided. Finally this yields to a front loading of quality control activities to a point as early as possible in the development process. In our work we focus on embedded reactive systems especially in the field of automotive software. Our current research targets at new kinds of test coverage criteria which reflect the systems requirements rather than structural aspects of models.