Unique identification of elements in evolving models : towards fine-grained traceability in model-driven engineering

Model-driven engineering (MDE) is a widely accepted methodology in software engineering. At the same time, the ability to retrace the engineering process is an important success factor for software projects. In MDE, however, such traceability is often impeded by the inadequate management of model evolution. Although models have a very fine-grained structure, their different revisions and variants are prevalently managed as monoliths in a file-based software configuration management (SCM). This causes the identification problem: if the fine-grained elements are not assigned with globally unique identifiers, we cannot identify them over time. If such identifiers would be given, they can be misleading. As a consequence, we cannot comprehend the evolution of elements and traceability relationships among the elements cannot be managed sufficiently. This thesis presents a novel solution to the identification problem. It establishes a representation to describe the history of a model and its fine-grained elements inside. The key feature of the representation is a new kind of traceability relationship, called identification links. They allow us to identify elements of a given revision in other revisions or variants of the model. The identification is even applicable to anonymous elements and model fragments. It provides us with a broad spectrum of opportunities: e.g. management of fine-grained traceability links, evolution analysis, merging of development branches. Due to the expression of model evolution in the history representation, we are further able to capture the changes that have been applied to the traced elements. This thesis further presents an algorithm to infer the identification links automatically. The approach does not rely on persistent identifiers, but it utilizes a similarity-based model comparison technique to locate the model elements in other revisions. The algorithm and the history representation have been implemented in a prototype. It is metamodel and tool independent and can work with an arbitrary SCM. Existing modeling environments do not have to be modified. Traceability information and evolution information is accessible through a service interface and can thus be integrated in arbitrary tools. The evaluation of our approach by means of controlled experiments with data from real models attested excellent precision and recall values for the identification of model elements over time. Furthermore, different evolution analysis tools have already been built on our approach, which documents the practical applicability of our solution.Die modellgetriebene Entwicklung ist eine weit verbreitete Methode zur Softwareentwicklung. Die ungeeignete Versionierung von Modellen verhindert jedoch oftmals die Nachverfolgbarkeit des Entwicklungsprozesses. Trotz ihrer feinkörnigen Struktur werden Modelle oft monolithisch auf Basis dateibasierter Konfigurationsmanagementsysteme verwaltet. Modellelemente können in diesem Fall nicht über die Zeit hinweg identifiziert werden, weil globale Identifizierer entweder fehlen oder irreführend sein können. Aufgrund dieses Identifikationsproblems können Änderungen an Modellelementen nur sehr schwer nachvollzogen werden. Außerdem können Referenzen zur Nachverfolgbarkeit zwischen Elementen verschiedener Revisionen nicht sinnvoll verwaltet werden. Diese Dissertation löst das Identifikationsproblem. Sie führt eine Repräsentation ein, mit der die Historie von Modellen und deren feinkörnigen Elementen abgebildet werden kann. Ein zentraler Bestandteil dieser Repräsentation sind Identifizierungslinks, die es ermöglichen ein gegebenes Element in anderen Revisionen oder Varianten des Modells wiederzufinden. Der Ansatz unterstützt auch anonyme Elemente und komplette Modellfragmente. Diese neuartige Identifizierung ermöglicht z.B. die Verwaltung von feinkörniger Nachverfolgbarkeitsinformation, die Analyse von Modellevolution oder das Mischen von Entwicklungszweigen. Da die Repräsentation auch die Evolution eines Modells abbilden kann, können die Veränderungen identifizierter Elemente besser erfasst werden. Zudem wird in dieser Dissertation ein Algorithmus entwickelt, mit dem Identifizierungslinks zwischen Modellelementen verschiedener Revisionen inferiert werden. Dieser stützt sich nicht auf persistente Identifizierer, sondern nutzt einen ähnlichkeitsbasierten Differenzalgorithmus, um Elemente in anderen Revisionen wiederzufinden. Der Algorithmus und die Historienrepräsentation wurden in einem modelltyp- und werkzeugunabhängigen Prototyp implementiert, der mit beliebigen Konfigurationsmanagementsystemen zusammenarbeitet, ohne dass diese angepasst werden müssen. Die Informationen zur Nachverfolgbarkeit und Evolution von Modellelementen sind über eine Programmierschnittstelle abfragbar, die sich in beliebigen Werkzeugen nutzen lässt. Der beschriebene Ansatz wurde mit kontrollierten Experimenten auf Basis realer Modellhistorien erfolgreich evaluiert. Darüber hinaus wurde seine praktische Anwendbarkeit durch verschiedene darauf aufbauende Werkzeuge zur Evolutionsanalyse belegt

Some issues in the 'archaeology' of software evolution

During a software project's lifetime, the software goes through many changes, as components are added, removed and modified to fix bugs and add new features. This paper is intended as a lightweight introduction to some of the issues arising from an `archaeological' investigation of software evolution. We use our own work to look at some of the challenges faced, techniques used, findings obtained, and lessons learnt when measuring and visualising the historical changes that happen during the evolution of software

Some issues in the 'archaeology' of software evolution

During a software project's lifetime, the software goes through many changes, as components are added, removed and modified to fix bugs and add new features. This paper is intended as a lightweight introduction to some of the issues arising from an `archaeological' investigation of software evolution. We use our own work to look at some of the challenges faced, techniques used, findings obtained, and lessons learnt when measuring and visualising the historical changes that happen during the evolution of software

Mining domain-specific edit operations from model repositories with applications to semantic lifting of model differences and change profiling

Model transformations are central to model-driven software development. Applications of model transformations include creating models, handling model co-evolution, model merging, and understanding model evolution. In the past, various (semi-) automatic approaches to derive model transformations from meta-models or from examples have been proposed. These approaches require time-consuming handcrafting or the recording of concrete examples, or they are unable to derive complex transformations. We propose a novel unsupervised approach, called Ockham, which is able to learn edit operations from model histories in model repositories. Ockham is based on the idea that meaningful domain-specifc edit operations are the ones that compress the model diferences. It employs frequent subgraph mining to discover frequent structures in model diference graphs. We evaluate our approach in two controlled experiments and one real-world case study of a large-scale industrial model-driven architecture project in the railway domain. We found that our approach is able to discover frequent edit operations that have actually been applied before. Furthermore, Ockham is able to extract edit operations that are meaningful—in the sense of explaining model diferences through the edit operations they comprise—to practitioners in an industrial setting. We also discuss use cases (i.e., semantic lifting of model diferences and change profles) for the discovered edit operations in this industrial setting. We fnd that the edit operations discovered by Ockham can be used to better understand and simulate the evolution of models

Automatic Generation of Trace Links in Model-driven Software Development

Traceability data provides the knowledge on dependencies and logical relations existing amongst artefacts that are created during software development. In reasoning over traceability data, conclusions can be drawn to increase the quality of software. The paradigm of Model-driven Software Engineering (MDSD) promotes the generation of software out of models. The latter are specified through different modelling languages. In subsequent model transformations, these models are used to generate programming code automatically. Traceability data of the involved artefacts in a MDSD process can be used to increase the software quality in providing the necessary knowledge as described above. Existing traceability solutions in MDSD are based on the integral model mapping of transformation execution to generate traceability data. Yet, these solutions still entail a wide range of open challenges. One challenge is that the collected traceability data does not adhere to a unified formal definition, which leads to poorly integrated traceability data. This aggravates the reasoning over traceability data. Furthermore, these traceability solutions all depend on the existence of a transformation engine. However, not in all cases pertaining to MDSD can a transformation engine be accessed, while taking into account proprietary transformation engines, or manually implemented transformations. In these cases it is not possible to instrument the transformation engine for the sake of generating traceability data, resulting in a lack of traceability data. In this work, we address these shortcomings. In doing so, we propose a generic traceability framework for augmenting arbitrary transformation approaches with a traceability mechanism. To integrate traceability data from different transformation approaches, our approach features a methodology for augmentation possibilities based on a design pattern. The design pattern supplies the engineer with recommendations for designing the traceability mechanism and for modelling traceability data. Additionally, to provide a traceability mechanism for inaccessible transformation engines, we leverage parallel model matching to generate traceability data for arbitrary source and target models. This approach is based on a language-agnostic concept of three similarity measures for matching. To realise the similarity measures, we exploit metamodel matching techniques for graph-based model matching. Finally, we evaluate our approach according to a set of transformations from an SAP business application and the domain of MDSD

Evolution of domain-specific languages depending on external libraries

L'ingénierie dirigée par les modèles est une approche qui s'appuie sur l'abstraction pour exprimer davantage les concepts du domaine. Ainsi, les ingénieurs logiciels développent des langages dédiés (LD) qui encapsulent la structure, les contraintes et le comportement du domaine. Comme tout logiciel, les LDs évoluent régulièrement. Cette évolution peut se produire lorsque l'un de ses composants ou le domaine évolue. L'évolution du domaine ainsi que l'évolution des composants du LD et l'impact de cette évolution sur ceux-ci ont été largement étudiés. Cependant, un LD peut également dépendre sur d'éléments externes qui ne sont pas modélisées. Par conséquent, l'évolution de ces dépendances externes affecte le LD et ses composants. Actuellement, les ingénieurs logiciels doivent évoluer le LD manuellement lorsque les dépendances externes évoluent. Dans ce mémoire, nous nous concentrons sur l'évolution des librairies externes. Plus spécifiquement, le but de cette thèse est d'aider les ingénieurs logiciels dans la tâche d'évolution. À cette fin, nous proposons une approche qui intègre automatiquement les changements des librairies externes dans le LD. De plus, nous offrons un LD qui supporte l'évolution des librairies Arduino. Nous évaluons également notre approche en faisant évoluer un éditeur de modélisation interactif qui dépend d'un LD. Cette étude nous permet de montrer la faisabilité et l'utilité de notre approche.Model-driven engineering (MDE) is an approach that relies on abstraction to further express domain concepts. Hence, language engineers develop domain-specific languages (DSLs) that encapsulates the domain structure, constraints, and behavior. Like any software, DSLs evolve regularly. This evolution can occur when one of its components or the domain evolves. The domain evolution as well as the evolution of DSL components and the impact of such evolution on them has been widely investigated. However, a DSL may also rely on external dependencies that are not modeled. As a result, the evolution of these external dependencies affects the DSL and its components. This evolution problem has yet to be addressed. Currently, language engineers must manually evolve the DSL when the external dependencies evolve. In this thesis, we focus on the evolution of external libraries. More specifically, our goal is to assist language engineers in the task of evolution. To this end, we propose an approach that automatically integrates the changes of the external libraries into the DSL. In addition, we offer a DSL that supports the evolution of the Arduino libraries. We also evaluate our approach by evolving an interactive modeling editor that depends on a DSL. This study allows us to demonstrate the feasibility and usefulness of our approach

Towards efficient comparison of change-based models

Comparison of large models can be time-consuming since every element has to be visited, matched, and compared with its respective element in other models. This can result in bottlenecks in collaborative modelling environments, where identifying differences between two versions of a model is desirable. Reducing the comparison process to only the elements that have been modified since a previous known state (e.g., previous version) could significantly reduce the time required for large model comparison. This paper presents how change-based persistence can be used to localise the comparison of models so that only elements affected by recent changes are compared and to substantially reduce comparison and differencing time (up to 90% in some experiments) compared to state-based model comparison

Innovations for Requirements Analysis, From Stakeholders' Needs to Formal Designs

14th MontereyWorkshop 2007 Monterey, CA, USA, September 10-13, 2007 Revised Selected PapersWe are pleased to present the proceedings of the 14thMontereyWorkshop, which took place September 10–13, 2007 in Monterey, CA, USA. In this preface, we give the reader an overview of what took place at the workshop and introduce the contributions in this Lecture Notes in Computer Science volume. A complete introduction to the theme of the workshop, as well as to the history of the Monterey Workshop series, can be found in Luqi and Kordon’s “Advances in Requirements Engineering: Bridging the Gap between Stakeholders’ Needs and Formal Designs” in this volume. This paper also contains the case study that many participants used as a problem to frame their analyses, and a summary of the workshop’s results

The Automatic Assessment of Multiple Artefacts: An Investigation into Design Diagrams and Their Implementations

As the Higher Education sector has moved towards student-centred learning so too has the growth in electronic support for learning. E-assessment has been a part of this growth as increasingly assessment and its feedback is seen as an integral part of the students’ learning process. Mature e-assessment systems exist, particularly where answers to questions are restricted to a prescribed list of alternatives. However, for free response artefacts, where there is a limited restriction placed on answers to questions, automated assessment systems are embryonic. This dissertation presents an investigation into the automated assessment of free response artefacts. Design diagrams and their accompanying source code implementations are examples of free response artefacts. A case study is developed that investigates how to automatically generate formative feedback for a design diagram by utilizing its accompanying implementation. The dissertation presents a two-staged solution, initially analysing the design diagram in isolation before comparing it with the implementation. A framework for this approach has been developed and tested using a tool applied to coursework submitted by undergraduate computer science students. The tool was evaluated by comparing the formative feedback comments generated by the tool with those produced by a team of computer science educators. Evaluation was undertaken via two Likert questionnaires, one completed by students and one completed by a team of computer scientists. The results presented are favourable, with the majority of comments produced by the tool being seen to be as least as good as those generated by the computer science educators

Fujaba days 2009 : proceedings of the 7th international Fujaba days, Eindhoven University of Technology, the Netherlands, November 16-17, 2009

Fujaba is an Open Source UML CASE tool project started at the software engineering group of Paderborn University in 1997. In 2002 Fujaba has been redesigned and became the Fujaba Tool Suite with a plug-in architecture allowing developers to add functionality easily while retaining full control over their contributions. Multiple Application Domains Fujaba followed the model-driven development philosophy right from its beginning in 1997. At the early days, Fujaba had a special focus on code generation from UML diagrams resulting in a visual programming language with a special emphasis on object structure manipulating rules. Today, at least six rather independent tool versions are under development in Paderborn, Kassel, and Darmstadt for supporting (1) reengineering, (2) embedded real-time systems, (3) education, (4) specification of distributed control systems, (5) integration with the ECLIPSE platform, and (6) MOF-based integration of system (re-) engineering tools. International Community According to our knowledge, quite a number of research groups have also chosen Fujaba as a platform for UML and MDA related research activities. In addition, quite a number of Fujaba users send requests for more functionality and extensions. Therefore, the 7th International Fujaba Days aimed at bringing together Fujaba developers and Fujaba users from all over the world to present their ideas and projects and to discuss them with each other and with the Fujaba core development team