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

Transforming OCL to PVS: Using Theorem Proving Support for Analysing Model Constraints

The Unified Modelling Language (UML) is a de facto standard language for describing software systems. UML models are often supplemented with Object Constraint Language (OCL) constraints, to capture detailed properties of components and systems. Sophisticated tools exist for analysing UML models, e.g., to check that well-formedness rules have been satisfied. As well, tools are becoming available to analyse and reason about OCL constraints. Previous work has been done on analysing OCL constraints by translating them to formal languages and then analysing the translated constraints with tools such as theorem provers. This project contributes a transformation from OCL to the specification language of the Prototype Verification System (PVS). PVS can be used to analyse and reason about translated OCL constraints. A particular novelty of this project is that it carries out the transformation of OCL to PVS by using model transformation, as exemplified by the OMG's Model-Driven Architecture. The project implements and automates model transformations from OCL to PVS using the Epsilon Transformation Language (ETL) and tests the results using the Epsilon Comparison Language (ECL )

Tool Paper: A Lightweight Formal Encoding of a Constraint Language for DSMLs

International audienceDomain Specific Modeling Languages (dsmls) plays a key role in the development of Safety Critical Systems to model system requirements and implementation. They often need to integrate property and query sub-languages. As a standardized modeling language, ocl can play a key role in their definition as they can rely both on its concepts and textual syntax which are well known in the Model Driven Engineering community. For example, most dsmls are defined using mof for their abstract syntax and ocl for their static semantics as a metamodeling dsml. OCLinEcore in the Eclipse platform is an example of such a metamodeling dsml integrating ocl as a language component in order to benefit from its property and query facilities. dsmls for Safety Critical Systems usually provide formal model verification activities for checking models completeness or consistency, and implementation correctness with respect to requirements. This contribution describes a framework to ease the definition of such formal verification tools by relying on a common translation from a subset of ocl to the Why3 verification toolset. This subset was selected to ease efficient automated verification. This framework is illustrated using a block specification language for data flow languages where a subset of ocl is used as a component language

Analyzing Semantic Properties of OCL Operations by Uncovering Interoperational Relationships

The OCL (Object Constraint Language) as part of the UML (Unified Modeling Language) is a rich language with different collection kinds (sets, multi-sets, sequences) and a large variety of operations defined thereon. Without negating the strong correlation between both fields we can say that these operations have their origin partly in logic (like the operations forAll and exists) and partly in computer science, in particular database systems (like the operation select). Some of these operations may be expressed in terms of other operations. This paper presents a systematic study of relationships which hold between OCL features like the mentioned operations. Apart from presenting the relationships between operations in a conceptual way, the relationships are described by a formal metamodel allowing systematic and computer supported access to the operation relationships by querying an underlying formal description

On validation of ATL transformation rules by transformation models

International audienceModel-to-model transformations constitute an important ingredient in model-driven engineering. As real world transformations are complex, systematic approaches are required to ensure their correctness. The ATLAS Transformation Language (ATL) is a mature transformation language which has been successfully applied in several areas. However, the executable nature of ATL is a barrier for the validation of transformations. In contrast, transformation models provide an integrated structural description of the source and target metamodels and the transformation between them. While not being executable, transformation models are well-suited for analysis and verification of transformation properties. In this paper, we discuss (a) how ATL transformations can be translated into equivalent transformation models and (b) illustrate how these surrogates can be employed to validate properties of the original transformation

Optimierte Suche von Modellinstanzen UML/OCL-Beschreibungen in USE

National audienceKonzeptuelle Modelle sind ein wichtiges Element modellgetriebener Softwareentwicklung, sowohl in der Beschreibung von Systemen als auch in der Metamodellierung domänenspezifischer Sprachen. Zu ihrer Beschreibung haben sich UML und OCL (und angelehnte Sprachen) als ein de facto Standard durchgesetzt. Validierung und Verifikation der Modelle sind hierbei wichtige Instrumente zur Sicherstellung der Modellqualität. Die Sprache ASSL (A Snapshot Sequence Language) bietet die Möglichkeit durch imperative Programmierung auf Modellebene und Backtracking konforme Instanzen systematisch zu erzeugen. Der White-Box-Ansatz ASSL ergänzt Black-Box-Ansätze, welche die Modellinstanziierung durch Abbildung auf (bspw.) ein Problem der relationalen Logik lösen. Dieser Beitrag beschreibt, wie die durch ASSL-Programme aufgespannten Suchräume durch Ausnutzung der Modellabdeckung der OCL-Constraints und der Modellstruktur erheblich verkleinert werden können und gibt einen Ausblick darauf, wie bestehende Black-Box-Ansätze in ASSL integriert werden können, um innerhalb eines imperativen Rahmens Teilinstanziierungen deklarativ beschreiben zu können

ArchiTRIO: a UML-compatible language for architectural description and its formal semantics

ArchiTRIO [14] is a formal language, which complements UML 2.0 concepts with a formal, logic-based notation that allows users to state system-wide properties, both static and dynamic, including real- time constraints. In this paper we present the semantics of the core con- cepts of the ArchiTRIO language. As the core elements of ArchiTRIO coincide with those of UML 2.0 (operation, interface, port, class), the semantics of ArchiTRIO provides also a formal definition for the basic concepts on which UML 2.0 is built

Diversity of graph models and graph generators in mutation testing

When custom modeling tools are used for designing complex safety-critical systems (e.g., critical cyber-physical systems), the tools themselves need to be validated by systematic testing to prevent tool-specific bugs reaching the system. Testing of such modeling tools relies upon an automatically generated set of models as a test suite. While many software testing practices recommend that this test suite should be diverse, model diversity has not been studied systematically for graph models. In the paper, we propose different diversity metrics for models by generalizing and exploiting neighborhood and predicate shapes as abstraction. We evaluate such shape-based diversity metrics using various distance functions in the context of mutation testing of graph constraints and access policies for two separate industrial DSLs. Furthermore, we evaluate the quality (i.e., bug detection capability) of different (random and consistent) model generation techniques for mutation testing purposes

Towards a K Semantics for OCL

International audienceWe give a formal definition to a significant subset of the Object Constraint Language (OCL) in the K framework. The chosen subset includes the usual arithmetical, Boolean (including quantifiers), and string expressions; collection expressions (including iterators and navigation); and pre/post conditions for methods. Being executable, our definition provides us, for free, with an interpreter for the chosen subset of OCL. It can be used for free in K definitions of languages having OCL as a component We illustrate some of the advantages of K by comparing our semantical definition of OCL with the official semantics from the language's standard. We also report on a tool implementing our definition that users can try online.Nous donnons une sémantique à un sous-ensemble significatif du langage OCL (Object Constraint Langage) dans le cadre formel K. Le sous-ensemble choisi inclut les expressions habituelles arithmétiques, logiques (y compris avec quantifications), et de type chaîne de caractères; les expressions de type collection (y compris les itérateurs et la navigation); et les pre/post conditions pour les méthodes des classes. Notre définition est exécutable et produit par construction un interpréteur pour le sous-ensemble d'OCL choisi. L'interpréteur peut être inclus comme composante dans d'autre langages définis en K qui incluent OCL en tant que sous-langage. Nous illustrons les avantages de notre sémantique en la comparant avec la sémantique issue de la norme (standard) OCL. Enfin, nous présentons un outil, disponible en ligne, qui implémente notre approche