Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-04-11T19:28:47Z No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-12T14:32:03Z (GMT) No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-12T14:32:03Z (GMT). No. of bitstreams: 2 Dissertação - Nayara de Souza Silva - 2017.pdf: 2066646 bytes, checksum: 95e09b89bf69fe61277b09ce9f1812a6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-07 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The process of developing computer systems takes into account many stages, in which some are more necessary than others, depending on the purpose of the application. The implementation stage is always necessary, indisputably. Sometimes the requirements analysis and testing phases are neglected. And, generally, the part of formal verification correctness is intended for few applications. The use of model checkers has been exploited in the task of validating a behavioral specification in its appropriate level of abstraction, notably specifications validation of critical systems, especially when they involve the preservation of human life, when the existence of errors entails huge financial loss or when deals with information security. Therefore, it proposes to apply formal verification techniques in the validation of the vehicular safety system Avoiding Doored System, considered as critical, in order to verify if the implemented system faithfully meets the requirements for it proposed. For that, it was used as a tool to verify its correctness the Specification and Verification System - PVS, detailing and documenting all the steps employed in the process of specification and formal verification. K / O processo de desenvolvimento de sistemas computacionais leva em conta muitas etapas, nos quais umas são tidas mais necessárias que outras, dependendo da finalidade da aplica- ção. A etapa de implementação sempre é necessária, indiscutivelmente. Por vezes as fases de análise de requisitos e de testes são negligenciadas. E, geralmente, a parte de verifica- ção formal de corretude é destinada a poucas aplicações. O uso de verificadores de modelos tem sido explorado na tarefa de validar uma especificação comportamental no seu nível adequado de abstração, sobretudo, na validação de especificações de sistemas críticos, principalmente quando estes envolvem a preservação da vida humana, quando a existência de erros acarreta enorme prejuízo financeiro ou quando tratam com a segurança da informa- ção. Diante disso, se propõe aplicar técnicas de verificação formal na validação do sistema de segurança veicular Avoiding Doored System, tido como crítico, com o intuito de atestar se o sistema implementado atende, fielmente, os requisitos para ele propostos. Para tal, foi utilizada como ferramenta para a verificação de sua corretude o Specification and Verification System - PVS, detalhando e documentando todas as etapas empregadas no processo de especificação e verificação formal. Pal

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.

This work deals with the problem of visual representation of Pi-calculus expressions. The theoretical part of this paper discusses general principles of process algebras as well as specific properties of individual models, with a focus on Pi-calculus. Also included is the comparison of several text and graphical representations of expressions. The main part of the thesis deals with the design and implementation of an application for converting text representation of expressions into graphical representation. In addition to the text and graphical representation, an internal tree representation designed to work with expressions within the application is also proposed. The thesis also describes algorithms for finding feasible reductions, performing reductions and expression simplification that operate with the proposed tree representation.

Development of software for electronic systems in the aviation industry is strongly regulated by pre-defined standards. The aviation industry spends significant costs of development in ensuring flight safety and showing conformance to these standards. Some safety requirements can be satisfied by performing formal verification. Formal verification is seen as a way to reduce costs of showing conformance of software with the requirements or formal specifications. Therefore, the correctness of formal specifications is critical. Writing formal specifications is at least as difficult as developing software [36]. This work proposes an approach to generate formal specifications from example data. This example data illustrates the natural language requirements and represents the ground truth about the system. This work eases the task of an engineer who has to write formal specifications by allowing the engineer to specify the example data instead. The use of a relationship model and a marking syntax and semantics are proposed that make the creation of formal specifications goal oriented. The evaluation of the approach shows that the proposed syntax and semantics capture more information than is strictly needed to generate formal specifications. The relationship model reduces the computational load and only produces formal specifications that are interesting for the engineer.

There have been numerous studies on formal methods but little utilisation of formal methods in the commercial world. This can be attributed to many factors, such as that few specialists know how to use formal methods. Moreover, the use of mathematical notation leads to the perception that formal methods are difficult. Formal methods can be described as system design methods by which complex computer systems are built using mathematical notation and logic. Formal methods have been used in the software development world since 1940, that is to say, from the earliest stage of computer development. To date, there has been a slow adoption of formal methods, which are mostly used for mission-critical projects in, for example, the military and the aviation industry. Researchers worldwide are conducting studies on formal methods, but the research mostly deals with path planning and control and not the runtime verification of autonomous systems. The main focus of this dissertation is the question of how to increase the pace at which formal methods are adopted in the business or commercial world. As part of this dissertation, a framework was developed to facilitate the use of formal methods in the commercial world. The framework mainly focuses on education, support tools, buy-in and remuneration. The framework was validated using a case study to illustrate its practicality. This dissertation also focuses on different types of formal methods and how they are used, as well as the link between formal methods and other software development techniques. An ERP system specification is presented in both natural language (informal) and formal notation, which demonstrates how a formal specification can be derived from an informal specification using the enhanced established strategy for constructing a Z specification as a guideline. Success stories of companies that are applying formal methods in the commercial world are also presented. / School of Computing

: leaves 122-134 / There have been numerous studies on formal methods but little utilisation of formal methods in the commercial world. This can be attributed to many factors, such as that few specialists know how to use formal methods. Moreover, the use of mathematical notation leads to the perception that formal methods are difficult. Formal methods can be described as system design methods by which complex computer systems are built using mathematical notation and logic. Formal methods have been used in the software development world since 1940, that is to say, from the earliest stage of computer development. To date, there has been a slow adoption of formal methods, which are mostly used for mission-critical projects in, for example, the military and the aviation industry. Researchers worldwide are conducting studies on formal methods, but the research mostly deals with path planning and control and not the runtime verification of autonomous systems. The main focus of this dissertation is the question of how to increase the pace at which formal methods are adopted in the business or commercial world. As part of this dissertation, a framework was developed to facilitate the use of formal methods in the commercial world. The framework mainly focuses on education, support tools, buy-in and remuneration. The framework was validated using a case study to illustrate its practicality. This dissertation also focuses on different types of formal methods and how they are used, as well as the link between formal methods and other software development techniques. An ERP system specification is presented in both natural language (informal) and formal notation, which demonstrates how a formal specification can be derived from an informal specification using the enhanced established strategy for constructing a Z specification as a guideline. Success stories of companies that are applying formal methods in the commercial world are also presented. / School of Computing / M. Sc. (Computing)

No description available.

Formal specification of software systems has been very promising. Critics against the end results of formal methods, that is, producing quality software products, is certainly rare. Instead, reasons have been formulated to justify why the adoption of the technique in industry remains limited. Some of the reasons are: • Steap learning curve; formal techniques are said to be hard to use. • Lack of a step-by-step construction mechanism and poor guidance. • Difficulty to integrate the technique into the existing software processes. Z is, arguably, one of the successful formal specification techniques that was extended to Object-Z to accommodate object-orientation. The Z notation is based on first-order logic and a strongly typed fragment of Zermelo-Fraenkel set theory. Some attempts have been made to couple Z with semi-formal notations such as UML. However, the case of coupling Object-Z (and also Z) and the Use Case Maps (UCMs) notation is still to be explored. A Use Case Map (UCM) is a scenario-based visual notation facilitating the requirements definition of complex systems. A UCM may be generated either from a set of informal requirements, or from use cases normally expressed in natural language. UCMs have the potential to bring more clarity into the functional description of a system. It may furthermore eliminate possible errors in the user requirements. But UCMs are not suitable to reason formally about system behaviour. In this dissertation, we aim to demonstrate that a UCM can be transformed into Z and Object-Z, by providing a transformation framework. Through a case study, the impact of using UCM as an intermediate step in the process of producing a Z and Object-Z specification is explored. The aim is to improve on the constructivity of Z and Object-Z, provide more guidance, and address the issue of integrating them into the existing Software Requirements engineering process. / Computer Science / M. Sc. (Computer Science)

Avec la plupart des méthodes formelles, un premier modèle peut être raffiné formellement en plusieurs étapes, jusqu'à ce que le raffinement final contienne assez de détails pour une implémentation. Ce premier modèle est généralement construit à partir de la description des besoins obtenue dans la phase d'analyse des exigences. Cette transition de la phase des exigences à la phase de spécification formelle est l'une des étapes les plus délicates dans la chaîne de développement formel. En fait, la construction de ce modèle initial exige un niveau élevé de compétence et beaucoup de pratique, d'autant qu'il n'existe pas de processus bien défini pour aider les concepteurs. Parallèlement à ce problème, il s'avère également que les exigences non-fonctionnelles sont largement marginalisées dans le processus de développement logiciel. Les pratiques industrielles actuelles consistent généralement à spécifier seulement les exigences fonctionnelles durant les premières phases de ce processus et à laisser la prise en compte des exigences non-fonctionnelles au niveau de l'implémentation. Pour surmonter ces problèmes, la thèse vise à définir un couplage entre un modèle d'exigences exprimé en SysML/KAOS et des spécifications formelles abstraites, tout en garantissant une distinction entre les exigences fonctionnelles et non-fonctionnelles dès la phase d'analyse des exigences. Pour cela, la thèse propose tout d'abord deux approches différentes (l'une dédiée au B classique et l'autre à Event-B) dans lesquelles des modèles formels abstraits sont construits progressivement à partir du modèle de buts fonctionnels SysML/KAOS. La thèse se focalise par la suite sur l'approche dédiée à Event-B afin de la compléter et l'enrichir en se servant de deux autres modèles SysML/KAOS qui décrivent les buts non-fonctionnels et leurs impacts sur les buts fonctionnels. Nous présentons différentes manières permettant d'injecter ces buts non-fonctionnels et leurs impacts dans les modèles abstraits Event-B déjà obtenus. Des liens de correspondance entre les buts non-fonctionnels et les différents éléments Event-B sont également établis afin de faciliter la gestion de l'évolution de ces buts. Les différentes approches proposées dans cette thèse ont été appliquées pour la spécification du composant de localisation qui est une partie critique d'un système de transport terrestre. L'approche dédiée à Event-B est implémentée dans l'outil SysKAOS2EventB, permettant ainsi de générer une architecture de raffinement Event-B à partir d'un modèle de buts fonctionnels SysML/KAOS. Cette mise en œuvre s'appuie principalement sur les technologies de transformation de modèles à modèles / With most of formal methods, an initial formal model can be refined in multiple steps, until the final refinement contains enough details for an implementation. Most of the time, this initial model is built from the description obtained by the requirements analysis. Unfortunately, this transition from the requirements phase to the formal specification phase is one of the most painful steps in the formal development chain. In fact, building this initial model requires a high level of competence and a lot of practice, especially as there is no well-defined process to assist designers. Parallel to this problem, it appears that non-functional requirements are largely marginalized in the software development process. The current industrial practices consist generally in specifying only functional requirements during the first levels of this process and in leaving the consideration of non-functional requirements in the implementation level. To overcome these problems, this thesis aims to define a coupling between a requirement model expressed in SysML/KAOS and an abstract formal specification, while ensuring a distinction between functional and non-functional requirements from the requirements analysis phase. For that purpose, this thesis proposes firstly two different approaches (one dedicated to the classical B and the other to Event-B) in which abstract formal models are built incrementally from the SysML/KAOS functional goal model. Afterwards, the thesis focuses on the approach dedicated to Event-B in order to complete it and enrich it by using the two other SysML/KAOS models describing the non-functional goals and their impact on functional goals. We present different ways to inject these non-functional goals and their impact into the obtained abstract Event-B models. Links of correspondance between the non-functional goals and the different Event-B elements are also defined in order to improve the management of the evolution of these goals. The different approaches proposed in this thesis have been applied to the specification of a localization component which is a critical part of a land transportation system. The approach dedicated to Event-B is implemented in the SysKAOS2EventB tool, allowing hence the generation of an Event-B refinement architecture from a SysML/KAOS functional goal model. This implementation is mainly based on the model-to-model transformation technologies

Dans cette thèse nous proposons un modèle temporel dans le cadre des machines à états abstraits (ASM). Une extension du langage de spécification ASM est développé qui correspond à ce modéle temporel pour le temps continu. L'extension du langage avec des constructions de temps permet de diminuer la taille de la spécification et donc de réduire la probabilité d'erreurs. La sémantique de l'extension du langage ASM est fournie et prend en compte les définitions des fonctions externes, les valeurs des délais et les choix de résolution des non-déterminismes. Un sous-système de vérification des propriétés exprimées en logique FOTL (FirstOrder Timed Logic) est développé. Un simulateur d'ASMs temporisées est développé et implémenté, il comprend un analyseur syntaxique, un interprète du langage, un sous-système de vérification des propriétés ainsi qu'une interface graphique / In this thesis a temporal model for abstract state machines (ASM) method is pro- posed. An extension of ASM specification language on the base of the proposed temporal model with continuous time is developed. The language extension helps to reduce the size of the specification hence to diminish the probability of an error. The semantics of the extended ASM language is developed which takes into account the definitions of external functions, the values of time delays and the method of non-determinism resolving. A subsystem for verification of user properties in the FOTL language is developed. A simulator prototype for ASMs with time is developed and implemented. It includes the parser of the timed ASM language, the interpreter, the verification subsystem and the graphical user interface