In this paper we motivate an Architecture Description Language (ADL) for mobile distributed systems based on the π-calculus. Different from other approaches, the non-functional properties, which are essential when mobile architectures are described, are treated in a flexible manner by inserting logical formulae for expressing and checking non-functional properties into π-calculus processes. A formal example is given to illustrate the approach before the constituents of the ADL are sketched.

L'Orienté Service (SOA) est un paradigme de conception qui facilite la construction d’applications extensibles et reconfigurables basées sur des artefacts réutilisables qui sont les services. Ceux-ci sont structurés via des interfaces bien définies et publiables et qui peuvent être dynamiquement découvertes.Beaucoup d’approches ont été proposées dans la littérature pour la réingénierie d’applications existantes développées dans des paradigmes pré-services, principalement l’orienté objet, vers SOA. L’objectif est de permettre de sauvegarder la valeur métier de ces d’applications tout en leur permettant de bénéficier des avantages de SOA. Le problème est que ces approches s'appuient sur des critères ad-hoc pour identifier correctement des services dans le code source des applications existantes.Par ailleurs, l'une des caractéristiques les plus distinctives d'une application orientée service est sa capacité de se reconfigurer dynamiquement et d'adapter son comportement en fonction de son contexte d'exécution. Cependant, dans les langages de description d'architecture (ADL) existants dont l’aspect de reconfiguration et pris en compte, les règles de reconfiguration sont représentées d'une manière ad-hoc; en général, elles ne sont pas modélisées d'une manière explicite mais enfouillées dans la description de l'architecture. D'une part, ceci engendre une difficulté de la gestion de la reconfiguration dynamique au niveau de l'architecture et d’autre part, la traçabilité de la description de la reconfiguration dynamique à travers les différents niveaux d'abstraction est difficile à représenter et à gérer.Afin de surmonter les problèmes précédents, nous proposons dans le cadre de cette thèse deux contributions. D'abord, nous proposons une approche d'identification de services basée sur un modèle de qualité où les caractéristiques des services sont étudiées, raffinées et réifiées en une fonction que nous utilisons pour mesurer la validité sémantique de ces services. La deuxième contribution consiste en une proposition d'un langage de description d'architecture orientée service (ADL) qui intègre la description de la variabilité architecturale. Dans cette ADL les services qui peuvent constituer l’architecture, les éléments de contexte dont les changements d’état sont à l’origine des changements architecturaux, les variantes des éléments architecturaux sélectionnées en fonction des états des éléments de contexte et le comportement architectural dynamique sont ainsi spécifiés de façon modulaire. / Service Oriented Architecture (SOA) is an architectural design paradigm which facilitates building and composing flexible, extensible and reusable service-oriented assets. These latter are encapsulated behind well-defined and published interfaces that can be dynamically discovered by third-party services. Before the advent of SOA, several software systems were developed using older technologies. Many of these systems still afford a business value, however they suffer from evolution and maintenance problems. It is advantageous to modernize those software systems towards service-based ones. In this sense, several re-engineering techniques propose migrating object-oriented applications towards SOA. Nonetheless, these approaches rely on ad-hoc criteria to correctly identify services in object-oriented legacy source code.Besides, one of the most distinguishing features of a service-oriented application is the ability to dynamically reconfigure and adjust its behavior to cope with changing environment during execution. However, in existing architecture description languages handling this aspect, reconfiguration rules are represented in an ad-hoc manner; reconfiguration scenarios are often implicit. This fact hinders a full management of dynamic reconfiguration at architecture level. Moreover, it constitutes a challenge to trace dynamic reconfiguration description/management at different levels of abstraction.In order to overcome the aforementioned problems, our contributions are presented in two axes: First, in the context of migrating legacy software towards SOA, we propose a service identification approach based on a quality measurement model, where service characteristics are considered, refined to measurable metrics in order to measure the semantic correctness of identified services. The second axis is dedicated to an Architecture Description Language (ADL) proposition that describes a variant-rich service-based architecture. In this modular ADL, dynamic reconfigurations are specified at architecture level. Moreover, the description is enriched with context and variability information, in order to enable a variability-based self-reconfiguration of architecture in response to context changes at runtime.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Architectural specification of real-time software systems is an activity that conveys analysis, knowledge and understanding of both the application domain and the parties involved in software construction. Architecture plays a key role in communication between stakeholders, in addition to planning the entire architectural process involved in the project. However, Architecture Description Languages (ADLs) have not been widely used in the industry. Another limiting factor for the e ff ective use of ADLs is the di ffi culty of these languages in e ff ectively expressing the architecture of complex systems. Considering this situation of di ffi culty in the e ff ective use of ADLs, the UML has been used in recent years to model the architecture. However, UML can not represent the important characteristics pertinent to real-time systems, such as security or real-time constraints. One of the advantages of the UML is the extensibility allowing the creation of profiles. In this sense, this work proposes using Systems Modeling Language (SysML), a UML profile, to model real-time systems architecture in two automotive systems, the airbag control system and the light control system. The objective of this work is to use UML and SysML to model and document the architecture and design of requirements traceability between software and systems elements, increasing the understanding of the project among the parties involved, and finally presenting SysML as a language for description of real-time software architecture. The ADL Architecture Analysis and Design Language (AADL) and SysML languages were compared to show the advantages of SysML. As a result, it was noticed that abstract features such as conditional deviations, loop, characteristics that are related to reality and consequently to the system can not be described in AADL. SysML has proved to be relevant in the context of architecture description, analysis, classification and modeling of real-time systems. The SysML Requirements diagram explicitly shows the various types of relationships between di ff erent requirements, the Block diagram enables the global view of the systems involved in a single project, the Internal Block diagram allows the internal view of the system under construction, the Activity diagram considers the behavioral view of the system. SysML concepts, articulated in the SysML Requirements, Activities, Blocks and Internal Blocks diagrams, are complementary, covering the purposes needed to describe the architecture of real-time systems. It is concluded that the proposed UML and SysML join technique provides elements to describe software requirements and their relationships with the system, to manage changes, to evolve and to trace requirements more easily, in addition to the communication being e ff ectively carried out between the stakeholders. This is important for the development of real-time systems because of the diversity of people / teams involved and influencing a wide range of design decisions. / A especificação da arquitetura de sistemas de software de tempo real é uma atividade que depreende análise, conhecimento e compreensão tanto do domínio da aplicação quanto das partes envolvidas na construção do software. A arquitetura tem um papel primordial na comunicação entre os stakeholders, além do planejamento de todo o processo arquitetural envolvido no projeto. Contudo, as Linguagens de Descrição de Arquiteturas (ADLs) não têm sido amplamente usadas na indústria. Outro fator limitador para o uso efetivo de ADLs é a dificuldade dessas linguagens em expressar efetivamente a arquitetura de sistemas complexos. Considerando essa situação de dificuldade do uso efetivo de ADLs, a UML tem sido utilizada nos últimos anos para modelagem da arquitetura. No entanto, a UML não consegue representar características importantes pertinentes a sistemas de tempo real, tais como segurança ou restrições de tempo real. Uma das vantagens da UML é a capacidade de extensão permitindo a criação de profiles. Neste sentido, este trabalho apresenta a Systems Modeling Language (SysML), um profile da UML, para modelagem da arquitetura de sistemas de tempo real em dois sistemas automotivos, o sistema de controle de airbag e o sistema de controle de faróis. Neste trabalho tem-se como objetivos utilizar a UML e a SysML para modelagem e documentação da arquitetura e delineamento de rastreabilidade de requisitos entre software e sistema, ampliando o entendimento do projeto entre as partes envolvidas, e por fim apresentar a SysML como uma linguagem para descrição da arquitetura de software de tempo real. As linguagens SysML e a ADL Architecture Analysis & Design Language (AADL) foram comparadas para mostrar as vantagens da SysML. Como resultado, foi percebido que características abstratas, tais como tomadas de decisão, repetição de uma funcionalidade (loop), características que são relacionadas a realidade e, consequentemente, ao sistema, não podem ser descritas em AADL. A SysML mostrou-se relevante no contexto da descrição, análise, classificação e modelagem de arquitetura para sistemas de tempo real. O diagrama de Requisitos da SysML mostra explicitamente os diversos tipos de relacionamentos entre diferentes requisitos, o diagrama de Blocos viabiliza a visão global dos sistemas envolvidos num único projeto, o diagrama de Blocos Internos possibilita a visão interna do sistema em construção, o diagrama de Atividades considera a visão comportamental do sistema. Os conceitos de SysML, articulados nos diagramas de Requisitos, Atividades, Blocos e Blocos Internos da SysML são complementares cobrindo os propósitos necessários para a descrição da arquitetura de sistemas de tempo real. Conclui-se que a técnica proposta da junção de UML e SysML fornece elementos para descrever requisitos de software e seus relacionamentos com o sistema, gerenciar mudanças, evoluir e rastrear requisitos mais facilmente, além da comunicação ser efetivamente realizada entre os stakeholders. Este aspecto é importante ao desenvolvimento de sistemas de tempo real, por causa da diversidade de pessoas / equipes envolvidas e que influenciam uma ampla série de decisões de projeto.