Domain Completeness of Model Transformations and Synchronisations

The intrinsic question of most activities in information science, in practice or science, is “Does a given system satisfy the requirements regarding its application?” Commonly, requirements are expressed and accessible by means of models, mostly in a diagrammatic representation by visual models. The requirements may change over time and are often defined from different perspectives and within different domains. This implies that models may be transformed either within the same domain-specific visual modelling language or into models in another language. Furthermore, model updates may be synchronised between different models. Most types of visual models can be represented by graphs where model transformations and synchronisations are performed by graph transformations. The theory of graph transformations emerged from its origins in the late 1960s and early 1970s as a generalisation of term and tree rewriting systems to an important field in (theoretical) computer science with applications particularly in visual modelling techniques, model transformations, synchronisations and behavioural specifications of models. Its formal foundations but likewise visual notation enable both precise definitions and proofs of important properties of model transformations and synchronisations from a theoretical point of view and an intuitive approach for specifying transformations and model updates from an engineer’s point of view. The recent results were presented in the EATCS monographs “Fundamentals of Algebraic Graph Transformation” (FAGT) in 2006 and its sequel “Graph and Model Transformation: General Framework and Applications” (GraMoT) in 2015. This thesis concentrates on one important property of model transformations and synchronisations, i.e., syntactical completeness. Syntactical completeness of model transformations means that given a specification for transforming models from a source modelling language into models in a target language, then all source models can be completely transformed into corresponding target models. In the same given context, syntactical completeness of model synchronisations means that all source model updates can be completely synchronised, resulting in corresponding target model updates. This work is essentially based on the GraMoT book and mainly extends its results for model transformations and synchronisations based on triple graph grammars by a new more general notion of syntactical completeness, namely domain completeness, together with corresponding verification techniques. Furthermore, the results are instantiated to the verification of the syntactical completeness of software transformations and synchronisations. The well-known transformation of UML class diagrams into relational database models and the transformation of programs of a small object-oriented programming language into class diagrams serve as running examples. The existing AGG tool is used to support the verification of the given examples in practice

On Modelling Communication in Ubiquitous Computing Systems using Algebraic Higher Order Nets

Ubiquitous computing systems (UCSs) are designed to participate almostimperceptibly in everyday life. To ensure a solid operation, a UCS heavily depends on a reliable and efficient communication between its distributed computing components. Moreover components can join and leave the system at any time.In order to guarantee high quality systems, the use of models is inevitable especiallyat an early stage of the development process where models are the only possibilityto address a system which does not yet exist in reality. Petri nets and graph transformationsystems are established, theoretically well-founded concepts for modellingand analysing complex systems.This paper presents a formal approach for modelling core aspects of the communicationin UCSs by using Algebraic Higher Order Nets with Individual Tokens andgraph transformation. The approach is suitable to cover the different aspects ofcommunication and enables the analysis of specific properties. The approach and itssuitability are illustrated based on a running example. The feasibility of embeddingthe approach in a broader context of modelling is demonstrated in applying it to areal world system: the Living Place Hamburg

Correctness of Generalisation and Customisation of Concurrent Model Synchronisation Based on Triple Graph Grammars

Triple graph grammars (TGGs) have been successfully applied to specify and analyse bidirectional model transformations. Recently, a formal approach to concurrent model synchronisation has been presented, where a source and a target modification have to be synchronised simultaneously. In this approach, conflicts between the given and propagated source or target model modifications are taken into account. A semi-automatic conflict resolution strategy is proposed, where a formal resolution strategy can be combined with a user-specific strategy. Up to now, our approach requires deterministic propagation operations. In this paper, we want to relax this condition and also consider non-deterministic (conflicting) operations which might require backtracking. For optimisation, we propose to eliminate conflicts between the operational rules of a TGG using the concept of filter NACs. Nevertheless, concurrent synchronisation is non-deterministic from a user perspective: The user may choose between forward synchronisation and backward synchronisation. Moreover, the conflict resolution strategy may result in several solutions from which the user has to select the most adequate one. Hence, we discuss different kinds of customisation of the synchronisation process and explain the impacts of the different strategies

Symbolic Execution of Satellite Control Procedures in Graph-Transformation-Based EMF Ecosystems

Symbolic execution is a well-studied technique for analysing the behaviour of software components with applications to test case generation. We propose a framework for symbolically executing satellite control procedures and generating test cases based on graph transformation techniques. A graph-based operational symbolic execution semantics is defined and the executed procedure models are used for generating test cases by performing model transformations. The approach is discussed based on a prototype implementation using the Eclipse Modelling Framework (EMF), Henshin and ECLiPSe-CLP tool ecosystem

On Modelling Communication in Ubiquitous Computing Systems using Algebraic Higher Order Nets

Ubiquitous computing systems (UCSs) are designed to participate almost imperceptibly in everyday life. To ensure a solid operation, a UCS heavily depends on a reliable and efficient communication between its distributed computing components. Moreover components can join and leave the system at any time. In order to guarantee high quality systems, the use of models is inevitable especially at an early stage of the development process where models are the only possibility to address a system which does not yet exist in reality. Petri nets and graph transformation systems are established, theoretically well-founded concepts for modelling and analysing complex systems. This paper presents a formal approach for modelling core aspects of the communication in UCSs by using Algebraic Higher Order Nets with Individual Tokens and graph transformation. The approach is suitable to cover the different aspects of communication and enables the analysis of specific properties. The approach and its suitability are illustrated based on a running example. The easibility of embedding the approach in a broader context of modelling is demonstrated in applying it to a real world system: the Living Place Hamburg

Towards Domain Completeness for Model Transformations Based on Triple Graph Grammars

The analysis of model transformations is a challenging research area within model driven engineering. Triple graph grammars (TGGs) have been applied in various transformation scenarios and their formal foundation has been a vital ground for general results concerning notions of correctness and completeness. This paper addresses existing gaps between practical scenarios and the formal results of TGGs concerning the notion of completeness. Since the source domain language of a model transformation is usually specified independently from the TGG, we use the notion of domain completeness, which requires that the model transformation has to provide a corresponding target model for each model of the source domain language. As main result, we provide a general method for showing that the source domain language is included in the language that is generated by the source rules of the TGG. This provides the first of two components for verifying domain completeness. The running example is the well studied object-relational mapping

Towards the Propagation of Model Updates along different Views in Multi-View Models

Models are the keystones in model-driven systems development. They describe systems at different layers of abstraction and with a focus to different domains. For each domain, dedicated domain specific visual modelling languages are used for model definitions with the idea to separate concerns to different domain experts. This enables precise problem and requirement definitions and should decrease efforts in developing and validating systems. We focus on multi-view models that are in relationship with source models by triple graph grammars. A multi-view model provides different views of the source model at different layers of abstraction but within the same DSL which is typically different from the DSL of the source model. In practice, elements in different views may overlap. We present an informal methodology for consistently propagating updates from one view to the other views and also to the source domain. We motivate our approach by multi-view models in a hospital scenario

Solving the FIXML2Code-case Study with HenshinTGG

Triple graph grammars (TGGs) provide a formal framework for bidirectional model transformations. As in practice, TGGs are primarily used in pure model-to-model transformation scenarios, tools for text-to-model and model-to-text transformations make them also applicable in text-to-text transformation contexts. This paper presents a solution for the text-to-text transformation case study of the Transformation Tool Contest 2014 on translating FIXML (an XML notation for financial transactions) to source code written in Java, C# or C++. The solution uses the HenshinTGG tool for specifying and executing model-to-model transformations based on the formal concept of TGGs as well as the Xtext tool for parsing XML content to yield its abstract syntax tree (text-to-model transformation) and serialising abstract syntax trees to source code (model-to-text transformation). The approach is evaluated concerning a given set of criteria