Test Sequence Generation from Communicating UML State Charts: An Industrial Application of Symbolic Transition Systems

Today's multimedia solutions in the automotive industry are complex and distributed hardware/software systems that interact with a multitude of different environments. Assuring the functional correctness of such software-enabled systems is a major issue to maintain and improve overall product quality. In this article we report on a test case generation approach, that allows engineers to employ well-known UML state chart models to deduce test cases fully automatically. Our approach is based on symbolic transition systems (STSs) and overcomes the intricacies resulting from straightforward application of enumerative test models (e.g. state space explosion). The derivation of the test sequences is performed by searching paths through the STS models with respect to their communication structure. By calculating the weakest preconditions of these paths the validity of the paths (and their related parameters) is ensured. Notably, our first empirical results on an industry showcase - a flashing indicator model developed with our industry partner - indicate that our model composition approach is applicable for both - systematic as well as randomized test case generation.