Keywords:
Astract: Model-Driven Engineering (MDE) gains momentum in academia as well as in practice. A wide variety of modeling tools is already available supporting different development tasks and advocating different modeling languages. In order to fully exploit the potential of MDE, modeling tools must work in combination, i.e., a seamless exchange of models between different modeling tools is crucial for MDE. Current best practices to achieve interoperability use model transformation languages to realize necessary mappings between concepts of the metamodels defining the modeling languages supported by different tools. However, the development of such mappings is still done in an ad-hoc and implementation-oriented manner which simply does not scale for large integration scenarios. The reason for this is twofold:
first, various modeling languages are not based on metamodeling standards but instead define proprietary languages rather focused on notational aspects, and second, existing model transformation languages are too fine granular to express mappings on a highlevel of abstraction and lack appropriate reuse mechanisms for already existing integration knowledge. This thesis proposes a comprehensive approach for realizing model-based tool integration which is inspired from techniques originating from the field of database integration, but employed in the context of MDE. For tackling the problem of missing metamodel descriptions, a semi-automatic approach for mining metamodels and models from textual language definitions is presented, representing a prerequisite for the subsequent steps which are based on metamodels and models, only. For raising the level of abstraction and the possibility of reuse of mappings between metamodels, a framework is proposed for building, applying, and executing reusable mapping operators. To demonstrate the applicability of the framework, it is applied for defining a set of mapping operators which are intended to resolve typical structural heterogeneities occurring between the core concepts used to define metamodels. Finally, for ensuring roundtrip capabilities of transformations, two approaches are presented how existing, non-roundtripping transformations can be enriched with rountrip capabilities.

Keywords: By-Example, model transformation, metamodel, automatic transformation, GMF
Astract: Many of the existing approaches for model transformation are metamodel-based and thus require detailed knowledge of the corresponding concepts and syntax. A solution often consists of a complete set of rules, which map meta elements between domains. These rules have to be provided by a third-party or the user herself. The latter case requires high levels of familiarity with both metamodels.
Model Transformation By-Example (MTBE) introduces a new concept. It enables the user to make use of her existing knowledge of the syntax and notation at the M1 level by deriving the rules automatically from mappings on the instance of a metamodel. The result of these generated rules and therefore the level of completeness can be applied continuously during the process and may lead to an iterative way of de ning the necessary mappings. To be able to generate a complete rule set, the suggested framework is able to provide an extension mechanism to alter the behaviour of the whole analysing component.
This work proposes the implementation of an MTBE-based framework on top of the Graphical Modeling Framework (GMF). The framework is realized by utilising the plug-in capabilities of Eclipse. The graphical components used to create the diagrams and mappings are realized through a GMF editor. An extensible analyser is applied to translate those mappings to the next abstraction level and to provide a weaving model as well as a set of ATL (Atlas Transformation Language) rules for later use in transforming models in both directions.
The core of the analyser consists of three algorithms, which provide the basic logic and can be extended to handle additional domains. The Eclipse mechanism through extension points is used to provide this capability. For testing and demonstration purposes two GMF Editors were developed, one for UML class diagrams and one for the ER domain.

Keywords: Model Driven Software Development, Model Transformation, GMF, By-Example
Astract: Model-Driven Engineering (MDE) is getting more and more attention as a viable alternative to the traditional code-centric software development paradigm.
With its progress, several model transformation approaches and languages have been developed in the past years. Most of these approaches are metamodel-based and therefore require knowledge of the abstract syntax of the modeling languages, which in contrast is not necessary for defining domain models using the concrete syntax of the respective languages.
To cope with shortcomings of current model transformation approaches we propose Model Transformation By-Example (MTBE), which is based on the by-example paradigm. Our approach allows the user to define semantic correspondences between concrete syntax elements with the help of special mapping operators. This is more user-friendly than directly specifying model transformation rules and mappings on the metamodel level. In general, the user's knowledge about the notation of the modeling language and the meaning of mapping operators is sufficient for the definition of model transformations. The definition of mapping operators is subject to extension, which has been applied for the definition of mapping operators for the structural and the behavioral modeling domain. But to keep things transparent and user-friendly, only a minimal set of mapping operators has been implemented. To compensate for the additional expressiveness inherent in common model transformation languages we apply reasoning algorithms on the models represented in concrete as well as in abstract syntax and on the metamodels to generate adequate transformation code.
In order to fulfill the requirements for a user-friendly application of MTBE, proper tool support and methods to guide the mapping and model transformation generation tasks are a must. Hence, a framework for MTBE was designed that builds on state-of-the-art MDE tools on the Eclipse platform, such as the Eclipse Modeling Framework (EMF), the Graphical Modeling Framework (GMF), the Atlas Transformation Language (ATL), and the Atlas Model Weaver (AMW). The decision to base our implementation on top of Eclipse and further Eclipse projects was driven by the fact, that there is a huge community we can address with our MTBE plug-in.
Finally, we evaluate our approach by means of two case studies in the areas of structural as well as behavioral modeling languages.

Keywords: Model Transformation, Business Process Models
Astract: Owing to company mergers and business to business interoperability, there is a need for model transformation in the area of business process modeling to facilitate model integration and model synchronisation. This need arises, on one hand, from the fact that there are many different business process modeling formalisms, for example the ADONIS Standard Modeling Method , UML 2.1 Activity Diagram, Event-driven Process Chains Method, and, the Business Process Modeling Notation.
These formalisms provide different ways to express and represent the same aspects of business process modeling. On the other hand, existing model transformation approaches, like ATL, QVT, and Fujaba, use very general concepts for transforming models for different purposes.
However, recurring structures have been observed when transforming models in the area of business process modeling. This leads to the assumption, that there are similar transformation problems in a distinct area. These recurring structures, however, are only inadequately supported by existing transformation approaches.
This thesis analyzes the different ways of how business process modeling aspects are represented in various business process modeling formalisms.
Furthermore, existing transformation approaches are evaluated concerning their suitability for transforming models in the area of business process modeling. Based on this evaluation, special requirements and solutions for model transformations in the area of business process modeling are derived. These solutions lead to the construction of the Model Morphing approach, which consists of an integrated metamodel and morphing methods which operate based on this metamodel. The Model Morphing approach makes it possible to concentrate on the specific transformation problems within a distinct domain. Furthermore, it reuses existing model transformation approaches and reduces the need for excellent programming skills when defining model transformations.

Keywords:
Astract: Ubiquitous web applications (UWA) are a new type of web applications which are accessed in various contexts, i.e. through different devices, by users with various interests, at anytime from anyplace around the globe. For such full-fledged, complex software systems, a methodologically sound engineering approach in terms of model-driven engineering (MDE) is crucial. Several modeling approaches have already been proposed that capture the ubiquitous nature of web applications, each of them having different origins, pursuing different goals and providing a pantheon of concepts. This paper aims to give an in-depth comparison of seven modeling approaches supporting the development of UWAs. This methodology is conducted by applying a detailed set of evaluation criteria and by demonstrating its applicability on basis of an exemplary tourism web application. In particular, five commonly found ubiquitous scenarios are investigated, thus providing initial insight into the modeling concepts of each approach as well as to facilitate their comparability. The results gained indicate that many modeling approaches lack a proper MDE foundation in terms of meta-models and tool support. The proposed modeling mechanisms for ubiquity are often limited, since they neither cover all relevant context factors in an explicit, self-contained, and extensible way, nor allow for a wide spectrum of extensible adaptation operations. The provided modeling concepts frequently do not allow dealing with all different parts of a web application in terms of its content, hypertext, and presentation levels as well as their structural and behavioral features. Finally, current modeling approaches do not reflect the crosscutting nature of ubiquity but rather intermingle context and adaptation issues with the core parts of a web application, thus hampering maintainability and extensibility. Different from other surveys in the area of modeling web applications, this paper specifically considers modeling concepts for their ubiquitous nature, together with an investigation of available support for MDD in a comprehensive way, using a well-defined as well as fine-grained catalogue of more than 30 evaluation criteria.