Designing and Documenting the Behavior of Software

The development and maintenance of today's software systems is an increasingly effort-consuming and error-prone task. A major cause of this problem is the lack of formal and human-readable documentation of software design. In practice, software design is often informally documented (e.g. texts in a natural language, `boxes-and-arrows' diagrams without well-defined syntax and semantics, etc.), or not documented at all. Therefore, the design cannot be properly communicated between software engineers, it cannot be formally analyzed, and the conformance of an implementation to the design cannot be formally verified.\ud \ud In this chapter, we address this problem for the design and documentation of the behavior implemented in procedural programs. We introduce a solution that consists of three components: The first component is a graphical language called VisuaL, which enables engineers to specify constraints on the possible sequences of function calls from a given program. Since the specifications may be inconsistent with each other, the second component of our solution is a tool called CheckDesign, which automatically\ud verifies the consistency between multiple specifications written in VisuaL. The third component is a tool called CheckSource, which automatically verifies that a given implementation conforms to the corresponding specifications written in VisuaL.\ud \ud This solution has been evaluated empirically through controlled experiments with 71 participants: 23 professional developers of ASML, and 49 Computer Science M.Sc. students. These experiments showed that, with statistical significance of 0.01, the solution reduced the effort of typical maintenance tasks by 75% and\ud prevented one error per 140 lines of source code

Quality-aware model-driven service engineering

Service engineering and service-oriented architecture as an integration and platform technology is a recent approach to software systems integration. Quality aspects ranging from interoperability to maintainability to performance are of central importance for the integration of heterogeneous, distributed service-based systems. Architecture models can substantially influence quality attributes of the implemented software systems. Besides the benefits of explicit architectures on maintainability and reuse, architectural constraints such as styles, reference architectures and architectural patterns can influence observable software properties such as performance. Empirical performance evaluation is a process of measuring and evaluating the performance of implemented software. We present an approach for addressing the quality of services and service-based systems at the model-level in the context of model-driven service engineering. The focus on architecture-level models is a consequence of the black-box character of services

Modelling mobile health systems: an application of augmented MDA for the extended healthcare enterprise

Mobile health systems can extend the enterprise computing system of the healthcare provider by bringing services to the patient any time and anywhere. We propose a model-driven design and development methodology for the development of the m-health components in such extended enterprise computing systems. The methodology applies a model-driven design and development approach augmented with formal validation and verification to address quality and correctness and to support model transformation. Recent work on modelling applications from the healthcare domain is reported. One objective of this work is to explore and elaborate the proposed methodology. At the University of Twente we are developing m-health systems based on Body Area Networks (BANs). One specialization of the generic BAN is the health BAN, which incorporates a set of devices and associated software components to provide some set of health-related services. A patient will have a personalized instance of the health BAN customized to their current set of needs. A health professional interacts with their\ud patients¿ BANs via a BAN Professional System. The set of deployed BANs are supported by a server. We refer to this distributed system as the BAN System. The BAN system extends the enterprise computing system of the healthcare provider. Development of such systems requires a sound software engineering approach and this is what we explore with the new methodology. The methodology is illustrated with reference to recent modelling activities targeted at real implementations. In the context of the Awareness project BAN implementations will be trialled in a number of clinical settings including epilepsy management and management of chronic pain