In dieser Dissertation, schaue ich auf objekt-orientierte Metamodellierung und wie sie verwendet werden kann, um Computersprachen zu beschreiben. Dabei, fokussiere ich mich nicht nur auf die Beschreibung von Sprachen, sondern auch auf die Verwendung von Sprachbeschreibungen zur automatischen Erzeugung von Sprachwerkzeugen aus Sprachbeschreibungen. Ich nutze die Idee von Metasprachen und Metawerkzeugen. Metasprachen werden verwendet um bestimmte Sprachaspekte, wie Notationen und Semantiken, zu beschreiben, und Metawerkzeuge werden verwendet um Sprachwerkzeuge wie Editoren und Interpreter aus entsprechenden Beschreibungen zu erzeugen. Diese Kombination von Beschreibung und automatischer Entwicklung von Werkzeugen ist als Domänenspezifische Modellierung (DSM) bekannt. Ich verwende DSM basierend auf objekt-orientierter Metamodellierung zur Beschreibung der wichtigen Aspekte ausführbarer Computersprachen. Ich untersuche existierende Metasprachen und Metawerkzeuge für die Beschreibung von Sprachvorkommen, ihrer konkreten Repräsentation und Semantik. Weiter, entwickle ich eine neue Plattform zur Beschreibung von Sprachen basierend auf dem CMOF-Modell der OMG MOF 2.x Empfehlungen. Ich entwickle eine Metasprache und Metawerkzeug für textuelle Notationen. Schlussendlich, entwickle ich eine graphische Metasprache und Metawerkzeug zur Beschreibung von operationaler Semantik von Computersprachen. Um die Anwendbarkeit der vorgestellten Techniken zu prüfen, nehme ich SDL, die Specification and Description Language, als einen Archetypen für textuell notierte Sprachen mit ausführbaren Instanzen. Für diesen Archetyp zeige ich, dass die präsentierten Metasprachen und Metawerkzeuge es erlauben solche Computersprachen zu beschreiben und automatisch Werkzeuge für diese Sprachen zu erzeugen. / In this thesis, I look into object-oriented meta-modelling and how it can be used to describe computer languages. Thereby, I do not only focus on describing languages, but also on utilising the language descriptions to automatically create language tools from language descriptions. I use the notion of meta-languages and meta-tools. Meta-languages are used to describe certain language aspects, such as notation or semantics, and meta-tools are used to create language tools, such as editors or interpreters, from corresponding descriptions. This combination of describing and automated development of tools is known as domain specific modelling (DSM). I use DSM based on object-oriented meta-modelling to describe all important aspects of executable computer languages. I look into existing meta-languages and meta-tools for describing language utterances, their concrete representation, and semantics. Furthermore, I develop a new platform to define languages based on the CMOF-model of the OMG MOF 2.x recommendations. I develop a meta-language and meta-tool for textual language notations. Finally, I develop a new graphical meta-language and meta-tool for describing the operational semantics of computer languages. To prove the applicability of the presented techniques, I take SDL, the Specification and Description Language, as an archetype for textually notated languages with executable instances. For this archetype, I show that the presented meta-languages and meta-tools allow to describe such computer languages and allow to automatically create tools for those languages.

Architectural documentation is crucial in the development process, as it helps developers understand the system’s architecture and make informed decisions. However, conventional documentation methods are often timeconsuming and error-prone since most of the work is done manually. This becomes even more ambiguous whendealing with complex systems and when requirements are prone to changing during the development process. This thesis addresses these challenges by exploring the potential benefits of utilizing object-oriented documentation tools and plugins to improve the efficiency of writing and maintaining architectural documentationwhile also making sure that the conveyed information is sufficient and understandable for junior developers. Moreover, it investigates the possibility of generating an easy-to-maintain context view with the use of metadatato display architectural information. The thesis employs both a qualitative case study as well as a rapid application development (RAD) approach.The case study involves interviewing junior developers to find patterns in what junior developers look for inregards to understanding a system’s architecture. Using the RAD approach, a prototype system is developedthat utilizes DollarDoc to treat documentation components as objects by being able to refer to these objectsfrom one file to another. The result shows how architectural documentation can be designed to effectively communicate critical aspects of the system’s architecture to junior developers by providing a clear overview of its components. Thiscontributes to a better understanding of the system’s functionality and purpose, leading to increased productivity and engagement. By using object-oriented documentation tools, the documentation structure becomesmore maintainable, allowing for automatic updates and reliable information.

The research is conducted in the area of software methodologies with the emphasis on the integration of legacy systems with the client/server environment. The investigation starts with identifying the characteristics of legacy systems in order to determine the features and technical characteristics required of an integration methodology. A number of existing methodologies are evaluated with respect to their features and technical characteristics in order to derive a synthesis for a generic methodology. This evaluation yields the meta primitives of a generic methodology. The revised spiral model (Boehm,1986; DuPlessis & Vander Wah,1992) is customised to arrive at a software process model which provides a framework for the integration of legacy systems with the client/server environment. The integration methodology is based on this process model. / Computing / M. Sc. (Information Systems)

The focus of the dissertation is on software quality assurance for object-oriented information systems development. A Quality Assurance Reference Model is proposed with aspects dealing with technical and managerial issues. A revised Spiral life cycle model is adopted as well as the Object Modelling Technique. The Quality Assurance Reference Model associates quality factors at various levels, quality criteria and metrics into a matrix framework that may be used to achieve quality assurance for all cycles of the Spiral Model. / Computing / M. Sc. (Information Systems)

The process control domain is intrinsically complex and dynamic. It has proved to be difficult to construct and maintain process control systems under the traditional software development methodologies. Object Orientation is the latest paradigm in software development. The reason for its widespread acceptance is that it allows the application of the principles of hierarchical structuring and component abstraction which is essential in building large systems. It also promotes component reusability which makes systems easier to maintain and modify. For the process control domain, these are important benefits. Furthermore, most process control systems have physical devices which can be modeled naturally as objects with the timing and performance issues of each object directly addressed. A Target System Reference Model which addresses various aspects of the process control domain is proposed within this dissertation. The objective is to provide a frame of reference within which a process control system can function. / Computing / M. Sc. (Computer Science)

Ce mémoire présente un patron d’architecture permettant, dans un contexte orientéobjet, l’exploitation d’objets appartenant simultanément à plusieurs hiérarchies fonctionnelles. Ce patron utilise un reasoner basé sur les logiques de description (web sémantique) pour procéder à la classification des objets dans les hiérarchies. La création des objets est simplifiée par l’utilisation d’un ORM (Object Relational Mapper). Ce patron permet l’utilisation effective du raisonnement automatique dans un contexte d’applications d’entreprise. Les concepts requis pour la compréhension du patron et des outils sont présentés. Les conditions d’utilisation du patron sont discutées ainsi que certaines pistes de recherche pour les élargir. Un prototype appliquant le patron dans un cas simple est présenté. Une méthodologie accompagne le patron. Finalement, d’autres utilisations potentielles des logiques de description dans le même contexte sont discutées. / This master thesis presents a software architectural pattern for use in an object oriented environment to simultaneously access objects in multiple functional hierarchies. A Description Logics (Semantic Web) reasoner is used to classify the objects in the hierarchies. Object creation is simplifed by the use of an ORM - Object Relational Mapper. The pattern effectively allows automatic reasoning procedures to be used in an enterprise application context. All concepts required to understand the architectural pattern and the tools are presented. Usage conditions for the pattern are discussed and research projects are presented to widen the pattern’s applicability. A prototype applying the pattern on a simple problem is presented. A methodology is also presented. Finally, other potential uses of Description Logics based automatic reasoning procedures are discussed.

Ce mémoire présente un patron d’architecture permettant, dans un contexte orientéobjet, l’exploitation d’objets appartenant simultanément à plusieurs hiérarchies fonctionnelles. Ce patron utilise un reasoner basé sur les logiques de description (web sémantique) pour procéder à la classification des objets dans les hiérarchies. La création des objets est simplifiée par l’utilisation d’un ORM (Object Relational Mapper). Ce patron permet l’utilisation effective du raisonnement automatique dans un contexte d’applications d’entreprise. Les concepts requis pour la compréhension du patron et des outils sont présentés. Les conditions d’utilisation du patron sont discutées ainsi que certaines pistes de recherche pour les élargir. Un prototype appliquant le patron dans un cas simple est présenté. Une méthodologie accompagne le patron. Finalement, d’autres utilisations potentielles des logiques de description dans le même contexte sont discutées. / This master thesis presents a software architectural pattern for use in an object oriented environment to simultaneously access objects in multiple functional hierarchies. A Description Logics (Semantic Web) reasoner is used to classify the objects in the hierarchies. Object creation is simplifed by the use of an ORM - Object Relational Mapper. The pattern effectively allows automatic reasoning procedures to be used in an enterprise application context. All concepts required to understand the architectural pattern and the tools are presented. Usage conditions for the pattern are discussed and research projects are presented to widen the pattern’s applicability. A prototype applying the pattern on a simple problem is presented. A methodology is also presented. Finally, other potential uses of Description Logics based automatic reasoning procedures are discussed.

Research has shown that there are gaps in knowledge between newly hired and experienced professionals and that some of these gaps are related to concepts, such as the concepts of object orientation. This problem, and the fact that most computer science majors want to work in the software industry, leads to questions regarding why these gaps exist and how students can be better prepared for their future careers. Against this background, this thesis addresses two theme-based perspectives that focus on students' views of concepts in Computer Science. The first theme-based perspective investigated the existence of potential Threshold Concepts in Computer Science. Such concepts should be troublesome, transformative, irreversible, and integrative. Qualitative methods have been mainly used and empirical data have been collected through semi-structured interviews, concept maps, and written stories. The results identified two Threshold Concepts, suggested several more, and then described the ways in which these concepts have transformed students. The second theme-based perspective took a phenomenographic approach to find the variation in how students understand concepts related to the software profession. Data were collected via semi-structured interviews. In one study the interviews were held in connection with role-playing where students took on the role of a newly hired programmer. The results show a variety of ways to experience the addressed phenomena in the student collective, ranging from superficial views that often have a practical nature to more sophisticated understandings that reflect a holistic approach, including a professional point of view. Educators can use the results to emphasize concepts that are important from students' perspectives. The phenomenographic outcome spaces can help teachers to reflect upon their own ways of seeing contrasted with student conceptions. I have indicated how variation theory can be applied to open more sophisticated ways of seeing, which in this context stresses the professional aspects to help students prepare for becoming professional software developers.

The research is conducted in the area of software methodologies with the emphasis on the integration of legacy systems with the client/server environment. The investigation starts with identifying the characteristics of legacy systems in order to determine the features and technical characteristics required of an integration methodology. A number of existing methodologies are evaluated with respect to their features and technical characteristics in order to derive a synthesis for a generic methodology. This evaluation yields the meta primitives of a generic methodology. The revised spiral model (Boehm,1986; DuPlessis & Vander Wah,1992) is customised to arrive at a software process model which provides a framework for the integration of legacy systems with the client/server environment. The integration methodology is based on this process model. / Computing / M. Sc. (Information Systems)

The focus of the dissertation is on software quality assurance for object-oriented information systems development. A Quality Assurance Reference Model is proposed with aspects dealing with technical and managerial issues. A revised Spiral life cycle model is adopted as well as the Object Modelling Technique. The Quality Assurance Reference Model associates quality factors at various levels, quality criteria and metrics into a matrix framework that may be used to achieve quality assurance for all cycles of the Spiral Model. / Computing / M. Sc. (Information Systems)