Enrico Biermann

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.

Precise Semantics of EMF Model Transformations by Graph Transformation

Model transformation is one of the key activities in model-driven software development. An increasingly popular technology to define modeling languages is provided by the Eclipse Modeling Framework (EMF). Several EMF model transformation approaches have been developed, focusing on different transformation aspects. To validate model transformations wrt. functional behavior and correctness, a formal foundation is needed. In this paper, we define EMF model transformations as a special kind of typed graph transformations using node type inheritance. Containment constraints of EMF model transformations are translated to a special kind of EMF model transformation rules such that their application leads to consistent transformation results only. Thus, we identify a kind of EMF model transformations which behave like algebraic graph transformations. As a consequence, the rich theory of algebraic graph transformation can be applied to these EMF model transformations to show functional behavior and correctness. We illustrate our approach by selected refactorings of simplified statechart models.

Formal foundation of consistent EMF model transformations by algebraic graph transformation

Model transformation is one of the key activities in model-driven software development. An increasingly popular technology to define modeling languages is provided by the Eclipse Modeling Framework (EMF). Several EMF model transformation approaches have been developed, focusing on different transformation aspects. To validate model transformations with respect to functional behavior and correctness, a formal foundation is needed. In this paper, we define consistent EMF model transformations as a restricted class of typed graph transformations using node type inheritance. Containment constraints of EMF model transformations are translated to a special kind of graph transformation rules such that their application leads to consistent transformation results only. Thus, consistent EMF model transformations behave like algebraic graph transformations and the rich theory of algebraic graph transformation can be applied to these EMF model transformations to show functional behavior and correctness. Furthermore, we propose parallel graph transformation as a suitable framework for modeling EMF model transformations with multi-object structures. Rules extended by multi-object structures can specify a flexible number of recurring structures. The actual number of recurring structures is dependent on the application context of such a rule. We illustrate our approach by selected refactorings of simplified statechart models. Finally, we discuss the implementation of our concepts in a tool environment for EMF model transformations.

Generation of Sierpinski Triangles: A Case Study for Graph Transformation Tools

In this paper, we consider a large variety of solutions for the generation of Sierpinski triangles, one of the case studies for the AGTIVE graph transformation tool contest [15]. A Sierpinski triangle shows a well-known fractal structure. This case study is mostly a performance benchmark, involving the construction of all triangles up to a certain number of iterations. Both time and space performance are involved. The transformation rules themselves are quite simple.

Lifting Parallel Graph Transformation Concepts to Model Transformation based on the Eclipse Modeling Framework

Model transformation is one of the key concepts in model-driven software development. An increasingly popular technology to define modeling languages is provided by the Eclipse Modeling Framework (EMF). Several EMF model transformation approaches have been developed, focusing on different transformation aspects. This paper proposes parallel graph transformation introduced by Ehrig and Kreowski as a suitable framework for modeling EMF model transformations with multi-object structures. Multi-object structures at transformation rule level provide a convenient way to describe the transformation of structures with a variable number of recurring structures, dependent on concrete model instances. Parallel graph transformation means the simultaneous application of a set of transformation rules synchronized at the application of a kernel rule. We apply our extended EMF model transformation technique to model the simulation of statecharts with AND-states.

Petri Net Transformations

Abstract Petri Nets: A Uniform Approach and Rule-Based Refinement. PhD thesis, Technical University Berlin, 1996. Shaker Verlag. [23] J. Padberg. Categorical Approach to Horizontal Structuring and Refinement of High-Level Replacement Systems. Applied Categorical Structures, 7(4):371-403, 1999. [24] J. Padberg. Basic Ideas for Transformations of Specification Architectures. In Proc.Workshop on Software Evolution through Transformations (SET 02), volume 74 of ENTCS, 2002. [25] J. Padberg, H. Ehrig, and L. Ribeiro. Algebraic High-Level Net Transformation Systems. Mathematical Structures in Computer Science, 5(2):217-256, 1995. [26] J. Padberg, P. Schiller, and H. Ehrig. New Concepts for High-Level Petri Nets in the Application Domain of Train Control. In Proc. Symposium on Transportation Systems, pages 153-160, 2000. [27] J. Padberg and M. Urbasek. Rule-Based Refinement of Petri Nets: A Survey. In Proc. Petri Net Technology for Communication-Based Systems, volume 2472 of LNCS, pages 161-196. Springer, 2003. [28] W. Reisig. Petri Nets and Algebraic Specifications.

Introduction to AGG and EMF Tiger by modeling a Conference Scheduling System

In this paper, we focus on the Conference Scheduling System, a case study at the Tool Contest of Graph-Based Tools (GraBaTs) 2008. We took part in the contest with our graph transformation tool AGG and the Eclipse-based EMF model transformation tool EMF Tiger. We present the features of both tools and evaluate their abilities to model the Conference Scheduling System and to deal with additional contest assignments like model instance generation, property verification, and interoperability.

Parallel independence of amalgamated graph transformations applied to model transformation

The theory of algebraic graph transformation has proven to be a suitable underlying formal framework to reason about the behavior of model transformations. In order to model an arbitrary number of actions at different places in the same model, the concept of amalgamated graph transformation has been proposed. Rule applications of certain regularity are described by a rule scheme which contains multirules modeling elementary actions and a common kernel rule for their synchronization (amalgamation). The amalgamation theorem by Bohm et al. ensures that for two multi-rules, the application of the amalgamated rule yields the same result as two iterative rule applications, respecting their common kernel rule application. In this paper, we propose an extension of the amalgamation theorem to an arbitrary finite number of synchronous rule applications. The theorem is used to show parallel independence of amalgamated graph transformations by analyzing the underlying multi-rules. As example, we specify an excerpt of a model transformation from Business Process Models (BPM) to the Business Process Execution Language (BPEL).

Independence Analysis of Firing and Rule-based Net Transformations in Reconfigurable Object Nets

The main idea behind Reconfigurable Object Nets (RONs) is to support the visual specification of controlled rule-based net transformations of place/transition nets (P/T nets). RONs are high-level nets with two types of tokens: object nets (place/transition nets) and net transformation rules (a dedicated type of graph transformation rules). Firing of high-level transitions may involve firing of object net transitions, transporting object net tokens through the high-level net, and applying net transformation rules to object nets, e.g. to model net reconfigurations. A visual editor and simulator for RONs has been developed as a plug-in for ECLIPSE using the ECLIPSE Modeling Framework (EMF) and Graphical Editor Framework (GEF) plug-ins. The problem in this context is to analyze under which conditions net transformations and token firing can be executed in arbitrary order. This problem has been solved formally in a previous paper. In this contribution we present an extension of our RON tool which implements the analysis of conflicts between parallel enabled transitions, between parallel applicable net transformation rules (Church-Rosser property), and between transition firing and net transformation steps. The conflict analysis is applied to a RON simulating a distributed producer-consumer system.

Visual Modeling of Controlled EMF Model Transformation using HENSHIN

Abstract: The tool HENSHIN is an Eclipse plug-in supporting visual modeling and execution of rule-based EMF model transformations. This paper describes the recent extensions of HENSHIN by control structures for controlled rule applications. The control structures comprise well-known imperative structures like sequences and conditions on rule applications. Moreover, application conditions for individual rules may now be arbitrarily nested and combined by logical connectors. We present the extension of the visual EMF model transformation environment HENSHIN to edit and perform controlled EMF model transformations along an example modeling a reactive Web service-based application (personal mobility manager).