We elaborate on the theoretical foundation and practical application of the contract-based specification method originally developed in the Integrated Project SPEEDS [11], [9] for two key use cases in embedded systems design. We demonstrate how formal contract-based component specifications for functional, safety, and real-time aspects of components can be expressed using the pattern-based requirement specification language RSL developed in the Artemis Project CESAR, and develop a formal approach for virtual integration testing of composed systems based on such contract-specifications of subsystems. We then present a methodology for multi-criteria architecture evaluation developed in the German Innovation Alliance SPES on Embedded Systems.

We study the extension of applicability of system-level testing techniques to the construction of a consistent model of (legacy) systems under test, which are seen as black boxes. We gather observations via an automated test environment and systematically extend available test suites according to learning procedures. Testing plays two roles here: (i) as an application domain and (ii) as the enabling technology for the adopted learning technique. The benefits include enhanced error detection and diagnosis, both during the testing phase and the online test of deployed systems at customer sites. 1

The notion of an expressive interpretation was originally introduced by Cook in order to formulate completeness results for Hoare-style proof systems. An interpretation is called expressive for a programming language if the input/output relation of e

A refinement of the result that there is no sound and relatively complete proof system for a programming language if its partial correctness theory is undecidable even in finite interpretations is presented. By taking into account the computational complexity of this problem, information about structural properties of proof systems for a given programming language is obtained. The key in the proofs is the notion of an interpretation independent proof system. It is shown that ordinary systems are interpretation independent, but that such systems are limited in their power. It is proven that they can deal successfully only with assertions whose sets of finite models are in NPTIME. Some assertions about programs from E.M. Clarke's (1979) language L4 have a more complex (but still decidable) set of finite models. This substantiates why it was difficult to give a satisfactory proof system for this language. The author explains which features of Clarke's proof system allow problems of such complexity to be treated.>

Every proof system for (partial) correctness yields an enumeration procedure for correctness assertions. Other researchers have proved results on the existence of (sound and complete) enumeration procedures for assertions about programs from an acceptable programming language where the assertion language is first-order logic. It is shown that some of the assumptions are stronger than necessary, whereas others must not be weakened. Two novel procedures are given that work for more interpretations with a smaller oracle than those known up to now.>