Modeling and Statistical Testing of Real Time Embedded Automotive Systems by Combination of Test Models and Reference Models in MATLAB/Simulink

Embedded systems become increasingly complex and distributed. Although there is necessity for thourough testing, exhaustive validiation and verification is hardly possible in industry due to time and resource restrictions. In the past the reason for this has often been that it was to time-consuming to specify, to execute, and to evaluate test cases for the first design models and the integrated embedded system. In the meantime methods have become popular in industry that allow the automated generation, execution, and evaluation of test cases. In order to be able to automate these steps all necessary information must be integrated into the models that are the basis for the following steps. The complexity of the system, however, makes the evaluation and assessment of the behavior of the system even more complex. The growth of information needed for this comes along with it. The integration of this information into the model which is used for the generation of test cases is hardly feasible. In this paper we describe how this issue can be addressed by the combination of reference models in MATLAB/Simulink with test models. Time Usage Models (TUM) are employed as test models and provide the basis to generate all possible test scenarios. Model based statistical testing with consideration of time and durations is supported by TUMs. The reference models are used like an executable specification, providing information for the evaluation of the system to be tested. The test model can therefore be kept generic in order to be able to derive virtually any test case from the model, taking account of the potentially infinite sequence of inputs reactive systems might process. We applied the presented approach with a german automotive OEM for the validation and verification of the energy management system.