The specification of enterprise information systems using formal specification languages enables the formal verification of these systems. Reasoning about the properties of a formal specification is a tedious task that can be facilitated much through the use of an automated reasoner. However, set theory is a corner stone of many formal specification languages and poses demanding challenges to automated reasoners. To this end a number of heuristics has been developed to aid the Otter theorem prover in finding short proofs for set-theoretic problems. This dissertation investigates the applicability of these heuristics to next generation theorem provers. / Computing / M.Sc. (Computer Science)

La sécurité des systèmes d'information devient un enjeu préoccupant pour les organisations tant publiques que privées, car de tels systèmes sont pour la plupart universellement accessibles à partir de navigateurs Web. Parmi tous les aspects liés à la sécurité des systèmes d'information, c'est celui de la sécurité fonctionnelle qui est étudié dans cette thèse sous l'angle de la mise en œuvre de politiques de contrôle d'accès dans une architecture orientée services. L'élément de base de la solution proposée est un modèle générique qui introduit les concepts essentiels pour la conception de gestionnaires d'exécution de politiques de contrôle d'accès et qui établit une séparation nette entre le système d'information et les mécanismes de contrôle d'accès. L'instanciation de ce modèle conduit à un cadre d'applications qui comporte, entre autres, un filtre de contrôle d'accès dynamique. Cette thèse présente également deux méthodes systématiques d'implémentation de ce filtre à partir de politiques écrites en ASTD, une notation graphique formelle basée sur les statecharts augmentés d'opérateurs d'une algèbre de processus. La notation ASTD est plus expressive que la norme RBAC et ses extensions, la solution actuellement privilégiée dans l'industrie. La première méthode repose sur une transformation de politiques de contrôle d'accès, instanciées à partir de patrons de base exprimés en ASTD, en des processus BPEL. La deuxième méthode est basée sur une interprétation de spécifications ASTD par des processus BPEL. Dans les deux cas, les processus BPEL s'exécutent dans un moteur d'exécution BPEL et interagissent avec le système d'information. Ces deux méthodes permettent une implémentation automatique d'un cadre d'applications à partir de la spécification de départ. Finalement, un prototype a été réalisé pour chacune des deux méthodes afin de montrer leur faisabilité au niveau fonctionnel et de comparer leurs performances au niveau système / Nowadays information systems are, more than ever, available through Web browsers. Therefore, they become vulnerable against attack, which has made security an important issue for public and private organizations. This thesis examines in depth one aspect of information system security, namely functional security through access-control policy enforcement, when such systems are implemented in a service-oriented architecture framework. The foundation of the proposed solution is a generic model that introduces essential concepts to design enforcement managers for access-control policies and clearly separates responsibilities between the information system and access control mechanisms. Instantiation of this model results in a general framework, which encompasses many components including a dynamic access-control filter. This thesis also presents two systematic implementation methods for the dynamic access-control filter from policies expressed in ASTD, a formal and graphical notation based on statecharts enriched with process algebra operators. The ASTD notation is more expressive than the RBAC standard and its extensions, the widely used solution in software engineering. The first method is based on the transformation of access-control policies, instantiated from ASTD patterns, into BPEL processes. The second method is based on the interpretation of ASTD specifications by BPEL processes. In these two cases, the BPEL processes are deployed and executed in a BPEL engine, and interact with the information system. Both methods allow for automatic implementation of an enforcement framework from the initial specification. Finally, prototypes have been developed to illustrate both methods and show their feasibility at the functional level and their performance

Especificações formais são úteis para descrever o que um sistema deve fazer sem definir como, e, em virtude da sua natureza formal e da possibilidade de abstração, é possível analisá-las sistematicamente. No entanto, o uso de especificações formais como parte do desenvolvimento de software não constitui prática comum. Isso se dá, em parte, pelo fato de existirem apenas um pequeno número de metodologias e ferramentas adequadas que dêem suporte a esse desenvolvimento. O primeiro objetivo deste trabalho é propor uma metodologia de desenvolvimento que possibilite, a partir de uma especificação formal em notação Z, produzir uma implementação dessa especificação em Java. Essa metodologia centra-se na geração do esqueleto da aplicação Java e na instrumentação desse esqueleto com mecanismos de verificação de condições (invariantes, pré e pós-condições) e rastreamento de violações dessas condições. Através desses mecanismos, possibilita-se intercalar desenvolvimento formal e informal no processo global de desenvolvimento de software. O segundo objetivo é desenvolver uma ferramenta que implemente parte dessa metodologia, produzindo uma implementação parcial que deverá ser complementada pelo usuário. / Formal specifications are useful for describing what a system should do, without defining how, and, owing to its formal nature, it is possible to analyse them systematically. However useful formal specifications are, their usage as part of the software development process is rather rare. This is, in part, due to the scarcity of both methodologies and tools that support this development. The first goal of this work is to define a software development methodology that enables the developer to produce a Java application from a formal specification written in Z. This methodology will rely strongly on the generation of Java application skeletons and instrumentation of the generated code with means of verifying conditions (invariants, pre and post-conditions) e tracing violations of these conditions. Through this mechanisms, it is possible to mix formal and informal development in the global software development process. The second goal of this work is to develop a tool that will implement part of this methodology, producing a partial implementation that must be complemented by the developer.

A definição de requisitos tem sido reconhecida como uma das mais críticas e difíceis tarefas em engenharia de software. A necessidade de ferramentas de suporte é essencial. Nos dias de hoje, entre os vários métodos existentes para apoiar a fase de requisitos, destaca-se o SADT (Structured Analysis and Design Techniques) devido a sua capacidade de representar modelos. Este trabalho estabelece semântica para o método SADT, baseando-se na inter-relação do método aos sistemas de fluxo de dados (redes, grafos e máquinas de fluxo). Faz-se, inicialmente, uma abordagem operacional para a semântica de seus construtos básicos e, posteriormente discute-se a possibilidade de executar especificações através de simulação. Uma ferramenta para suportar o método SADT foi projetada e construída e é apresentada. Ela foi definida a partir de um modelo, denotado por uma classe, através de uma sintaxe abstrata. Essa ferramenta foi implementada no ambiente PROSOFT, fornecendo para o usuário mais de quarenta operações de apoio a construção/manipulação de diagramas. O trabalho também apresenta a especificação formal em VDM - Vienna Development Method, da semântica dos principais construtos do método SADT, bem como uma proposição de execução de especificações através de simulação são ainda indicadas direções nas quais o trabalho pode ser estendido. / The definition of systems requirements has been known as one of the most critical and dificult tasks as far as the software engineering is concerned. The need support is essential. Nowadays, among the various methods devised to support the phase of requirements, a special emphasis is given to the SADT method (Structured Analysis and Design Techniques), due to its capability of representing models. This work set semantic for the SADT method, based primarily upon the interrelation of the method to the systems of dataflow (nets, graphs and dataflow machines). It deals with an approach of operational semantics to its basic constructs, and it will, afterwards, discuss the possibility of carry out specifications by simulation. A tool was built to support the SADT method, and it was defined by a model denoted by a class, through an abstract syntax. This tool was implemented in the PROSOFT environment, providing for the user, more than forty support operations for the construction /manipulation of diagrams. This work also presents the formal specification of the semantics of the main constructs of the SADT method in VDM - Vienna Development Method; as well as an execution proposal of specifications through simulation. Directions have been indicated concerning the extension of the research.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.

Currently, the bulk of applications of Formal Concept Analysis (FCA) in software engineering have focussed on software maintenance and re-engineering. In this thesis we broaden the approach by applying FCA to a number of early-phase activities within the software engineering life-cycle. With respect to the requirements engineering phase, a case study is presented comparing two class hierarchies that model aspects of a mass-transit railway ticketing system. The first hierarchy was produced for an existing Object-Z specification of the system while the second was derived using FCA. Contrasting the two hierarchies revealed that they were essentially the same, however, the differences highlighted specification artefacts in the existing hierarchy. With respect to the design phase, the thesis discusses the use of FCA for the navigation and visualisation of Formal Specifications written in Z. In response to the continued call for formal methods tool support, we implement and explore a prototype specification browser that exploits the abstractions afforded by FCA. The research hypothesis is an integrated architecture for navigating formal specifications using FCA. This architecture is realised using ZML and ToscanaJ to produce a practical research tool. The thesis also includes the first broad survey of FCA in the domain of software engineering and an FCA-based methodology for surveying academic literature in general.