Florian Mantz

DPF Workbench: A Diagrammatic Multi-Layer Domain Specific (Meta-)Modelling Environment

This paper presents the DPFWorkbench, a diagrammatic tool for domain specific modelling. The tool is an implementation of the basic ideas from the Diagram Predicate Framework (DPF), which provides a graph based formalisation of (meta)modelling and model transformations. The DPFWorkbench consists of a specification editor and a signature editor and offers fully diagrammatic specification of domain-specific modelling languages. The specification editor supports development of metamodelling hierarchies with an arbitrary number of metalevels; that is, each model can be used as a metamodel for the level below. The workbench also facilitates the automatic generation of domain-specific specification editors out of these metamodels. Furthermore, the conformance relations between adjacent metalevels are dynamically checked by the use of typing morphisms and constraint validators. The signature editor is a new component that extends the DPF Workbench with functionality for dynamic definition of predicates. The syntax of the predicates are defined by a shape graph and a graphical icon, and their semantics are defined by validators. Those predicates are used to add constrains on the underlying graph. The features of the DPF Workbench are illustrated by a running example presenting a metamodelling hierarchy for workflow modelling in the health care domain.

Co-transformation of graphs and type graphs with application to model co-evolution

Meta-modeling has become the key technology to define do–main-specific modeling languages in model-driven engineering. Since do–main-specific modeling languages often change quite frequently, concepts are needed for the coordinated evolution of their meta-models as well as of their models, and possibly other related artifacts. In this paper, we present a new approach to the co-transformation of graphs and type graphs and show how it can be applied to model co-evolution. This means that models are specified as graphs while model relations, especially type-instance relations, are defined by graph morphisms specifying type conformance of models to their meta-models. Hence, meta-model evolution and accompanying model migrations are formally defined by co-transformations of instance and type graphs. In our approach, we clarify the type conformance of co-transformations, the completeness of instance graph transformations wrt. their type graph modifications, and the reflection of type graph transformations by instance graph transformations. Finally, we discuss strategies for automatically deducing instance graph transformation rules from given type graph transformations.

Co-evolving meta-models and their instance models: A formal approach based on graph transformation

Abstract Model-driven engineering focuses on models as primary artifacts of the software development process, which means programs are mainly generated by model-to-code transformations. In particular, modeling languages tailored to specific domains promise to increase the productivity of software developers and the quality of generated software. Modeling languages, however, evolve over time and therefore, existing models have to be migrated accordingly. The manual migration of models tends to be tedious and error-prone, therefore tools have been developed to (partly) automate this process. Nevertheless, the migration results may not always be well-defined. In this article, we provide a formal framework for model migration which is independent of specific modeling approaches. We treat modeling languages, formalized by meta-models, as well as models as graphs and consider their co-evolutions as coupled graph transformations. In the same line, we study the conditions under which model migrations are well-defined. Existing solutions to model migration are either handwritten or default solutions that can hardly be customized. Here, we introduce a high-level specification approach, called model migration schemes, that supports automation and customization. Starting from a meta-model evolution rule, a default migration scheme can be automatically deduced and customized.

Well-formed Model Co-evolution with Customizable Model Migration

Model-driven engineering (MDE) is a software engineering discipline which focuses on models as the primary artifact of the software development process while programs are mainly generated by means of model-to-code transformations. In particular, modeling languages tailored to specific domains promise to increase the productivity and quality of software. Nevertheless due to e.g. evolving requirements, modeling languages evolve and existing models have to be migrated. Corresponding manual model migration is tedious and error-prone, therefore tools have been developed to (partly) automate this process. We follow the idea of considering such modeling language and model co-evolutions as related graph transformations ensuring a correct and unique typing of migrated models. In this paper, we present a general and formal construction of well-formed model migration schemes that are able to co-adapt any model of a given modeling language to a performed meta-model change. We show how appropriate model migration schemes can be constructed and discuss how they may be customized.

Customizable Model Migration Schemes for Meta-model Evolutions with Multiplicity Changes

Modeling languages tailored to specific application domains promise to increase the productivity and quality of model-driven software development. Nevertheless due to, for example, evolving requirements, modeling languages, and their meta-models evolve which means that existing models have to be migrated accordingly. In our approach, such co-evolutions are specified as related graph transformations ensuring well-typed model migration results. Model migrations are specified by transformation rules that can be automatically deduced from given meta-model evolution rules and further customized to special needs. Up to now, meta-model constraints have not been taken into account. In this paper, we extend our approach to handle multiplicity constraints and illustrate this extension using several examples.

A declarative and bidirectional model transformation approach based on graph co-spans

In Model Driven Engineering (MDE) models are the main artefacts of the software development process. Model transformations are used both in the software development phase and for verification and simulation of the system behaviour. Hence, tools and languages for describing model transformations are essential in MDE. While many practical transformation languages and tools have been proposed, there is still the need for formal foundations of model transformations. In this work we propose a novel formalisation of model transformations based on graph transformation and category theory. Differently from current approaches, our formalisation is based on the definition of integration models and co-span rules, being purely declarative and bidirectional by nature. Transformations are performed by rule amalgamation in a way that guarantees confluence and termination, and we show correctness and completeness of this mechanism with respect to the specification.

Graph transformation concepts for meta-model evolution guaranteeing permanent type conformance throughout model migration

Meta-modeling has become the key technology to define domain-specific modeling languages for model-driven engineering. However, these modeling languages can change quite frequently which requires the evolution of their meta-models as well as the co-evolution (or migration) of their models. In this paper, we present an approach towards meta-model model co-evolution based on graph transformation concepts that targets to consider this challenge in a formal setting. Models are specified as graphs while model relations, especially type-instance relations, are defined by graph morphisms specifying type conformance of models to their meta-models. We present a basic approach to automatic deduction of model migrations from meta-model evolution steps which are specified by single transformation rules. Throughout that migration process, type conformance is ensured permanently. A first implementation is given using existing technology, namely the Eclipse Modeling Framework (EMF) and the EMF model transformation tool Henshin which is based on graph transformation concepts. Our evolution approach is presented at two small evolution scenarios for Petri nets and state machines.

Customizing model migrations by rule schemes

Model-driven engineering (MDE) is a software engineering discipline focusing on models as the primary artifacts in the software development process while programs are mainly generated by means of model-to-code transformations. In particular, modeling languages tailored to specific application domains promise to increase the productivity and quality of software development. Nevertheless due to e.g. evolving requirements, modeling languages and their meta-models evolve which means that existing models have to be migrated correspondingly. In our approach, such co-evolutions are specified as related graph transformations ensuring well-typed model migration results. Based on our earlier work on co-transformations, we now consider the automatic deduction of migration rule schemes from given meta-model evolution rules. Rule schemes form the basis for user customizations on a high abstraction level. A rule scheme deduction algorithm is presented and several customized migration schemes for different co-evolution examples are discussed.

Co-Transformation of Type and Instance Graphs Supporting Merging of Types and Retyping

Algebraic graph transformation is a well-known rule-based approach to manipulate graphs that can be applied in several contexts. In this paper we use it in the context of model-driven engineering. Graph transformation rules usually specify changes to only one graph per application, however there are use cases such as model co-evolution where not only a single graph should be manipulated but also related ones. The co-transformation of type graphs together with their instance graphs has shown to be a promising approach to formalize model and meta-model co-evolution. In this paper, we extend our earlier work on co-evolution by allowing transformation rules that have less restrictions so that graph manipulations such as merging of types and retyping of graph elements are allowed.