International Journal of Software and Informatics 

Abstract: The new generation of collaborative IT systems poses great challenges to software engineering due to their evolving nature and their high quality requirements. In particular, the management of collaborative systems requires the integration of perspectives from IT management, software engineering and systems operation and a systematic way to handle changes. In this paper we will present the core ideas of Living Models – a novel paradigm of model–based development, management and operation of evolving service oriented systems. A core concern of Living Models is to support the cooperation of stakeholders from IT management, software engineering and systems operation by providing appropriate model-based abstractions and a focus on interdependencies. Based on this idea the running services together with their modelling environments constitute the basic unit of quality management and evolution. Living Models provides a coherent view of the quality status of the system (integrating the perspectives of all stakeholders) which evolves together with the running systems. This comes along with a software engineering process in which change is a first– class citizen. In this paper we will present ten core principles of Living Models together with three application scenarios.

Abstract: Specication of interactive distributed systems has been a challenge for decades. We present an overview of the specication techniques for these systems based on dataow networks and stream processing. It covers models of streams and specication of stream processing systems that are related to and based on the development method Focus invented by Manfred Broy and his group. We introduce a basic set of manipulator operations for streams, stream bundles, stream processing functions, and give a summary of related state- based specication techniques. Furthermore we sketch an overview of implementations for

Abstract: Conforming to protocol specifications is a critical issue in modern distributed software systems. Nowadays, complex service infrastructures, such as Voice-over-IP systems, are usually built by combining components of different vendors. If the components do not correctly implement the various protocol specifications, failures will certainly occur. In the case of emergency calls this may be even life-threatening. Functional black-box conformance testing, where one checks the conformance of the implemented protocol to a specification becomes therefore a major issue. In this work, we report on our experiences and findings when applying fault-based conformance testing to an industrial application. Besides a discussion on modeling and simplifications we present a technique that prevents an application from implementing particular faults. Faults are modeled at the level of the specification. We show how such a technique can be adapted to specifications with large state spaces and present results obtained when applying our technique to the Session Initiation Protocol and to the Conference Protocol. Finally, we compare our results to random and scenario based testing.