Stefan Jurack

Henshin: advanced concepts and tools for in-place EMF model transformations

The Eclipse Modeling Framework (EMF) provides modeling and code generation facilities for Java applications based on structured data models. Henshin is a new language and associated tool set for in-place transformations of EMF models. The Henshin transformation language uses pattern-based rules on the lowest level, which can be structured into nested transformation units with well-defined operational semantics. So-called amalgamation units are a special type of transformation units that provide a forall-operator for pattern replacement. For all of these concepts, Henshin offers a visual syntax, sophisticated editing functionalities, execution and analysis tools. The Henshin transformation language has its roots in attributed graph transformations, which offer a formal foundation for validation of EMF model transformations. The transformation concepts are demonstrated using two case studies: EMF model refactoring and meta-model evolution.

Towards a distributed modeling process based on composite models

The rising impact of software development in globally distributed teams strengthens the need for strategies that establish a clear separation of concerns in software models. Dealing with large, weakly modularized models and conflicting changes on interrelated models are typical obstacles to be witnessed. This paper proposes a structured process for distributed modeling based on the modularization technique provided by composite models with explicit interfaces. It provides a splitting activity for decomposing large models, discusses asynchronous and synchronous editing steps in relation to consistency management and provides a merge activity allowing the reuse of code generators. All main concepts of composite modeling are precisely defined based on category theory.

A component concept for typed graphs with inheritance and containment structures

Model-driven development (MDD) has become a promising trend in software engineering. The model-driven development of highly complex software systems may lead to large models which deserve a modularization concept to enable their structured development in larger teams. Graphs are a natural way to represent the underlying structure of visual models. Typed graphs with inheritance and containment are well suited to describe the essentials of models based on the Eclipse Modeling Framework (EMF). EMF models already support the physical distribution of model parts. Based on the concept of distributed graphs, we propose typed composite graphs with inheritance and containment to specify logical distribution structures of EMF models. The category-theoretical foundation of this kind of composite graphs forms a solid basis for the precise definition of typed composite graph transformations obeying inheritance and containment conditions.

Sufficient Criteria for Consistent Behavior Modeling with Refined Activity Diagrams

In use case-driven approaches to requirements modeling, UML activity diagrams are a wide-spread means for refining the functional view of use cases. Early consistency validation of activity diagrams is therefore desirable but difficult due to the semi-formal nature of activity diagrams. In this paper, we specify well-structured activity diagrams and define activities more precisely by pre- and post- conditions. They can be modeled by interrelated pairs of object diagrams based on a domain class diagram. This activity refinement is based on the theory of graph transformation and paves the ground for a consistency analysis of the required system behavior. A formal semantics for activity diagrams refined by pre- and post-conditions allows us to establish sufficient criteria for consistency. The semi-automatic checking of these criteria is supported by a tool for graph transformation.

Object Flow Definition for Refined Activity Diagrams

Activity diagrams are a well-known means to model the control flow of system behavior. Their expressiveness can be enhanced by using their object flow notation. In addition, we refine activities by pairs of pre- and post-conditions formulated by interrelated object diagrams. To define a clear semantics for refined activity diagrams with object flow, we use a graph transformation approach. Control flow is formalized by sets of transformation rule sequences, while object flow is described by partial dependencies between transformation rules. This approach is illustrated by a simple service-based on-line university calendar.

Towards Composite Model Transformations Using Distributed Graph Transformation Concepts

Model-based development of highly complex software systems leads to large models. Storing them in repositories offers the possibility to work with these models in a distributed environment. However, they are not modularized and thus, do not especially support distributed development. An alternative is to consider composite models such that several teams can work largely independently. In this paper, we consider a general approach to composite models and their transformation based on graph transformation concepts. To illustrate this approach, we present a concrete setting for composite models based on the Eclipse Modeling Framework (EMF). EMF models can be distributed over several sites. While remote references can express import relations, export and import interfaces are not explicitly defined. In our approach, we sketch composite models with explicit and implicit interfaces using concepts of distributed graph transformation and outline different kinds of composite model transformations.

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.

Transformation of Typed Composite Graphs with Inheritance and Containment Structures

Model-driven development (MDD) has become a promising trend in software engineering. The model-driven development of highly complex software systems may lead to large models which deserve a modularization concept to enable their structured development in larger teams. Graphs are a natural way to represent the underlying structure of visual models. Typed graphs with inheritance and containment structures are well suited to describe the essentials of models based on the Eclipse Modeling Framework (EMF). Composite graphs can specify the logical distribution of EMF models and therefore, can form the conceptual basis for composite modeling in model-driven development. This is done based on the formal foundation of distributed graphs. Moreover, this category-theoretical foundation allows for the precise definition of consistent composite graph transformations satisfying all inheritance and containment conditions.

Composite EMF modeling based on typed graphs with inheritance and containment structures

The rising paradigm of model-driven development (MDD) promises to be a new technique to control the complexity of today’s software systems. However, increasing complexity may lead to large models which may justify a logical and/or physical distribution into several component models for better manageability. The concurrent development by distributed teams is desirable and already common practice in conventional software development. Naive solutions as storing all models in a central repository may not be adequate for distributed software development. E.g. Open Source Development is performed by distributed developer teams working in independent projects.