Collaborative Verification-Driven Engineering of Hybrid Systems

Hybrid systems with both discrete and continuous dynamics are an important model for real-world cyber-physical systems. The key challenge is to ensure their correct functioning w.r.t. safety requirements. Promising techniques to ensure safety seem to be model-driven engineering to develop hybrid systems in a well-defined and traceable manner, and formal verification to prove their correctness. Their combination forms the vision of verification-driven engineering. Often, hybrid systems are rather complex in that they require expertise from many domains (e.g., robotics, control systems, computer science, software engineering, and mechanical engineering). Moreover, despite the remarkable progress in automating formal verification of hybrid systems, the construction of proofs of complex systems often requires nontrivial human guidance, since hybrid systems verification tools solve undecidable problems. It is, thus, not uncommon for development and verification teams to consist of many players with diverse expertise. This paper introduces a verification-driven engineering toolset that extends our previous work on hybrid and arithmetic verification with tools for (i) graphical (UML) and textual modeling of hybrid systems, (ii) exchanging and comparing models and proofs, and (iii) managing verification tasks. This toolset makes it easier to tackle large-scale verification tasks

OCL Tools Report based on the IDE4OCL Feature Model

Previously we have developed the idea of an Integrated Development Environment for OCL (IDE4OCL). Based on the OCL community's feedback we have also designed and published an IDE4OCL feature model. Here we present a report on selected OCL tools developed by the authors and their teams. Each author gives an overview of their OCL tool, provides a top level architecture, and gives an evaluation of the tool features in a web framework. The framework can also be used by other potential OCL users and tool developers. For users it may serve as an aid to choose a suitable tool for their OCL use scenarios. For tool developers it provides a comparative view for further development of the OCL tools. Our plans are to maintain the collected data and extend this web framework by further OCL tools. Additionally, we would like to encourage sharing of OCL development resources

A Feature Model for an IDE4OCL

An Integrated OCL Development Environment (IDE4OCL) can significantly improve the pragmatics and practice of OCL. Therefore we started a comprehensive requirement analysis with the long term vision of a multisite IDE4OCL project. In this paper we present a feature model for the IDE4OCL vision based on this analysis. In an earlier work we identified domain concepts, tool–level interactions with IDE4OCL, and use cases for OCL developers including a set predefined features. In the second step, we asked the OCL community members for their feedback on our proposal. Around 100 researchers, tool developers and practitioners who gained experience with OCL have voted in an online–survey. The results gave us a valuable insight in the needs of OCL usage both in usual and advanced OCL applications. One of the important results is a collection of features that have been proposed additionally to our predefined features. We analysed all the comments of the participants of the survey and consolidated them into an extended set of IDE4OCL features and eventually into a feature model

Metamodel-based model conformance and multiview consistency checking

Model-driven development, using languages such as UML and BON, often makes use of multiple diagrams (e.g., class and sequence diagrams) when modeling systems. These diagrams, presenting different views of a system of interest, may be inconsistent. A metamodel provides a unifying framework in which to ensure and check consistency, while at the same time providing the means to distinguish between valid and invalid models, that is, conformance. Two formal specifications of the metamodel for an object-oriented modeling language are presented, and it is shown how to use these specifications for model conformance and multiview consistency checking. Comparisons are made in terms of completeness and the level of automation each provide for checking multiview consistency and model conformance. The lessons learned from applying formal techniques to the problems of metamodeling, model conformance, and multiview consistency checking are summarized

Adding Graph Transformation Concepts to UML's Constraint Language OCL

AbstractThe Object Constraint Language OCL is an integral part of UML, the Unified Modeling Language standard. It has been added to UML as a logic-based sublanguage for the definition of class invariants and pre-/postconditions of operations. OCL is rather similar to a subset of the graph transformation language PROGRES, the so-called path expressions. These path expressions are used for similar purposes as OCL. In contrast to OCL, path expressions support functional abstraction and offer additional operators for conditional iteration and transitive closure. Furthermore, PROGRES possesses a visual query sublanguage and is equipped with a precise semantics definition. Based on our experiences with the development of PROGRES a number of modifications and extensions of OCL are suggested as recommendations for its forthcoming version 2.0

Construct by Contract: Construct by Contract: An Approach for Developing Reliable Software

This research introduces “Construct by Contract” as a proposal for a general methodology to develop dependable software systems. It describes an ideal process to construct systems by propagating requirements as contracts from the client’s desires to the correctness proof in verification stage, especially in everyday-used software like web applications, mobile applications and desktop application. Such methodology can be converted in a single integrated workspace as standalone tool to develop software. To achieve the already mentioned goal, this methodology puts together a collection of software engineering tools and techniques used throughout the software’s lifecycle, from requirements gathering to the testing phase, in order to ensure a contract-based flow. Construct by Contract is inclusive, regarding the roles of the people involved in the software construction process, including for instance customers, users, project managers, designers, developers and testers, all of them interacting in one common software development environment, sharing information in an understandable presentation according to each stage. It is worth to mention that we focus on the verification phase, as the key to achieve the reliability sought. Although at this point, we only completed the definition and the specification of this methodology, we evaluate the implementation by analysing, measuring and comparing different existing tools that could fit at any of the stages of software’s lifecycle, and that could be applied into a piece of commercial software. These insights are provided in a proof of concept case study, involving a productive Java Web application using struts framework