Model-based testing relies on behavior models for the generation of model traces: input and expected output---test cases---for an implementation. We use the case study of an automotive network controller to assess different test suites in terms of error detection, model coverage, and implementation coverage. Some of these suites were generated automatically with and without models, purely at random, and with dedicated functional test selection criteria. Other suites were derived manually, with and without the model at hand. Both automatically and manually derived model-based test suites detected significantly more requirements errors than hand-crafted test suites that were directly derived from the requirements. The number of detected programming errors did not depend on the use of models. Automatically generated model-based test suites detected as many errors as hand-crafted model-based suites with the same number of tests. A sixfold increase in the number of model-based tests led to an 11% increase in detected errors.

Abstract. Message sequence charts (MSCs) have proven to be a useful modeling technique especially within the requirements analysis phase of software development. MSCs, however, do not support the concept of broadcast communication, which is frequently used in technical applications. In this paper, we present an extension to MSCs for the modeling of broadcast interaction scenarios. Based on the mathematical framework of timed streams we also introduce a semantics for broadcast MSCs. We thoroughly discuss methodological benefits and semantic properties of this approach, consider alternative solutions, and address its scaleability with respect to complex real-time systems applications.

The definition of a transparent software architecture is one of the key issues in the early development phases for complex distributed and reactive software systems. In this paper, we show how to derive an architecture systematically for systems with communication models based on broadcasting. Adequate graphical description techniques for capturing interaction requirements and logical component architectures for broadcasting systems are unavailable so far. We introduce an extension to UML's sequence diagrams to capture broadcasting scenarios. Furthermore, we present methodological steps for constructively deriving structural and behavioral aspects of the architecture under consideration from the captured scenarios.