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A promising way to develop flexible software systems is to include models that are analyzed, modified and executed at runtime as an integrated part of the system. Building such model-integrating systems is a challenging task since the respective modeling languages have to be supported comprehensively at runtime, and these systems still need to be developable in a modular way by composing them from basic building blocks. Model-driven (MDD) and component-based development (CBD) are two established orthogonal approaches that can tackle the mentioned challenges. MDD is based on the use of models and modeling languages as first-class entities to systematically engineer software systems. CBD enables the engineering of modular systems by facilitating a divide-and-conquer approach with reuse. However, combining and aligning the individual principles from both approaches is an open research problem. In this article, we describe model-integrating development (MID), an engineering approach that enables the systematic development of component-based, model-integrating software. MID combines principles from MDD and CBD and is based on the central assumption that models and code shall be treated equally as first-class entities of software throughout its life cycle. In particular, MID leverages the added flexibility that comes with models at runtime, i.e., when models are an integral part of running software. The practicability of the proposed solution concept is rationalized based on a reference implementation that provides the basis for a thoroughly described and critically discussed feasibility study: a dynamic access control product line. The obtained benefits are presented in a distilled way, and future research challenges are identified. [ABSTRACT FROM AUTHOR]

Many future software systems will be distributed across a network, extensively providing different kinds of services for their users. These systems must be highly reliable and provide services when required. Reliability and availability must be engineered into software from the onset of its development, and potential problems must be detected in the early stages, when it is easier and less expensive to implement modifications. The software architecture design phase is the first stage of software development in which it is possible to evaluate how well the quality requirements are being met. For this reason, a method is needed for analyzing software architecture with respect to reliability and availability. In this paper, we define a framework for comparing reliability and availability analysis methods from the viewpoint of software architecture. Our contribution is the comparison of the existing analysis methods and techniques that can be used for reliability and availability prediction at the architectural level. The objective is to discover which methods are suitable for the reliability and availability prediction of today’s complex systems, what are the shortcomings of the methods, and which research activities need to be conducted in order to overcome these identified shortcomings. The comparison reveals that none of the existing methods entirely fulfill the requirements that are defined in the framework. The comparison framework also defines the characteristics required of new reliability and availability analysis methods. Additionally, the framework is a valuable tool for selecting the best suitable method for architecture analysis. Furthermore, the framework can be extended and used for other evaluation methods as well. [ABSTRACT FROM AUTHOR]

Integrating software components to produce large-scale software systems is an effective way to reuse experience and reduce cost. However, unexpected interactions among components when integrated into software systems are often the cause of failures. Discovering these composition errors early in the development process could lower the cost and effort in fixing them. This paper introduces a rigorous analysis approach to software design composition based on automated verification techniques. We show how to represent, instantiate and integrate design components, and how to find design composition errors using model checking techniques. We illustrate our approach with a Web-based hypermedia case study. [ABSTRACT FROM AUTHOR]