A goal-oriented approach to support the assurance process of self-adaptive systems under uncertainty

Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2019.Objetivos são entidades de primeira classe em um sistema auto-adaptativo (SAS) uma vez que eles guiam a auto-adaptação. Normalmente, SAS opera em ambientes dinâmicos e parcialmente desconhecidos, causando incerteza que o SAS deve endereçar para atingir seus objetivos. Ainda, apesar do ambiente, outras classes de incerteza já foram identificadas. Entretanto, essas diversas classes e suas fontes não são endereçadas sistematicamente por abordagens atuais durante todo o ciclo de vida do SAS. Reconhecer as diferentes classes e fontes de incertezas contribui para um entendimento mais claro sobre como elas impactam os objetivos e o comportamento do sistema, sendo assim, auxiliando o processo de garantias de SAS. Nós propomos uma abordagem orientada a objetivos que modela SAS com incerteza e gera modelos verificáveis para verificação do sistema em tempo de projeto e de execução. Em tempo de projeto, baseados em um modelo orientado a objetivos complementado com anotações de incerteza, nós geramos automaticamente: (i) um Processo de Decisão de Markov (MDP) na linguagem PRISM, e (ii) fórmulas paramétricas de confiabilidade e custo parametrizadas com incertezas. O MDP é utilizado por atividade de verificação de modelos probabilístico para dar suporte à análise e à verificação do sistema em tempo de projeto. As fórmulas paramétricas são meios para uma análise eficiente do SAS em tempo de execução, e para guiar a síntese de políticas de adaptação feita por engenheiros. Nesse trabalho, nós focamos nas propriedades de confiabilidade e custo, e avaliamo-las nos sistemas Tele Assistance System (TAS) e Body Sensor Network (BSN). Os resultados da validação são promissores e mostram que nossa abordagem é capaz de gerar modelos verificáveis de SAS com incertezas de forma escalável e confiável.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Goals are first-class entities in a self-adaptive system (SAS) as they guide the selfadaptation. A SAS often operates in dynamic and partially unknown environments, which cause uncertainty that the SAS has to address to achieve its goals. Moreover, besides the environment, other classes of uncertainty have been identified. However, these various classes and their sources are not systematically addressed by current approaches throughout the life cycle of the SAS. Recognizing the different classes and sources of uncertainty contributes to a clear understanding of how they impact system goals and behavior, therefore assisting the assurance process of SAS. We propose a goal-oriented approach that models SAS within uncertainty and generates verifiable models for system verification at both design- and runtime. At design time, based on a goal model augmented with uncertainty annotations, we automatically generate: (i) a Markov Decision Process (MDP) model in PRISM language, and (ii) reliability and cost parametric formulae with parameterized uncertainties. The MDP is used by probabilistic model checking activity to support system analysis and verification at design time. The parametric formulae provide means for efficient runtime analysis of SAS and guide the synthesis of adaptation policies by engineers. In this work, we focus on reliability and cost properties, for which we evaluate our approach on the Tele Assistance System (TAS) and the Body Sensor Network (BSN) system. The results of the validation are promising and show that our approach is able to generate scalable and trustworthy verifiable models of SAS under uncertainty

Verificando a boa formação de modelos GODA

Monografia (graduação)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2016.O framework GODA (Goal-Oriented Dependability Analysis) realiza análise de dependabilidade em modelos orientados a objetivos. Uma etapa importante é o processo de geração automática de modelo DTMC (Discrete-Time Markov Chains) a partir de um modelo CRGM (Contextual and Runtime Goal Model). O modelo CRGM apresenta notações específicas não testadas. Erros neste modelo podem acarretar em problemas na geração do modelo DTMC. Como o GODA é integrado à diferentes ferramentas, a atividade de teste funcional consegue verificar a funcionalidade geral deste framework. Esse trabalho teve como objetivo o desenvolvimento de uma suíte de testes que verifique a boa formação dos modelos CRGM. Para isso, foi escolhida a abordagem de teste funcional, utilizando o critério Teste Funcional Sistemático. A partir da especificação do programa, classes de equivalência foram definidas e, em seguidas, casos de teste foram identificados. A implementação dos testes foi feita utilizando a linguagem de programação Java, e o conjunto de testes foi automatizado utilizando a ferramenta JUnit. Os resultados mostraram falhas na validação de anotações utilizadas no modelo CRGM. O desenvolvimento da suíte de testes proposta foi importante para expor problemas que podem acarretar numa geração de modelos DTMC incorretos, devido a erros no CRGM.GODA (Goal-Oriented Dependability Analysis) framework performs dependability analysis on goal models. An important step is the CRGM (Contextual and Runtime Goal Model) to DTMC (Discrete-Time Markov Chains) automated code generation. CRGM has untested notations. Errors in this model could result in problems during the DTMC model generation. Since GODA integrates many different tools, functional testing activity can control the overall functionality of this framework. The aim of this work was the development of a test suit that verifies well formedness of the CRGM model. The functional testing approach was chosen, using the Systematic Functional Testing criterion. From de software specification, equivalence classes were defined and then test cases were identified. The tests were implemented in Java, and automated using JUnit. The results showed validation failures of CRGM notes. The development of the test suit proposed was important to expose problems that can lead to incorrect DTMC models due to errors in CRGM

Taming Uncertainty in the Assurance Process of Self-Adaptive Systems: a Goal-Oriented Approach

Goals are first-class entities in a self-adaptive system (SAS) as they guide the self-adaptation. A SAS often operates in dynamic and partially unknown environments, which cause uncertainty that the SAS has to address to achieve its goals. Moreover, besides the environment, other classes of uncertainty have been identified. However, these various classes and their sources are not systematically addressed by current approaches throughout the life cycle of the SAS. In general, uncertainty typically makes the assurance provision of SAS goals exclusively at design time not viable. This calls for an assurance process that spans the whole life cycle of the SAS. In this work, we propose a goal-oriented assurance process that supports taming different sources (within different classes) of uncertainty from defining the goals at design time to performing self-adaptation at runtime. Based on a goal model augmented with uncertainty annotations, we automatically generate parametric symbolic formulae with parameterized uncertainties at design time using symbolic model checking. These formulae and the goal model guide the synthesis of adaptation policies by engineers. At runtime, the generated formulae are evaluated to resolve the uncertainty and to steer the self-adaptation using the policies. In this paper, we focus on reliability and cost properties, for which we evaluate our approach on the Body Sensor Network (BSN) implemented in OpenDaVINCI. The results of the validation are promising and show that our approach is able to systematically tame multiple classes of uncertainty, and that it is effective and efficient in providing assurances for the goals of self-adaptive systems

La COVID-19 y la integración ante los desafíos de un nuevo orden mundial

When the pandemic passes, a fundamental post-pandemic stage comes in which we must face the profound changes in the International System that will lead to a new world order. These changes cover various fronts such as economics and geopolitics, social or environmental, and an instrument such as integration must be prepared to address these challenges in a cooperative, supportive, and consensual manner. In the economicsphere, there is a revaluation of the actions of the States through public policies, initially oriented primarily towards health, but which will lead to other issues of social policy in the field of employment, economic reactivation through new forms of productive chains and of establishing public policies aimed at prioritizing measures corresponding to a Welfare State, where the objectives of sustainable development acquire priority, as well as all the policies related to environmental problems. These measures will be accompanied by a revaluation of multilateral management through institutional reforms and global agreements, influenced at the same time by a great dispute of world leadership between the United States and China, but in a context of regionalization with different areas of the planet playing a leading role, such as East Asia and the Middle East. The countries of Latin America will achieve little individually and in a disorganized manner, which is why a challenge in the post-pandemic is to reactivate their integration processes to meet the enormous needs and requirements that must be addressed as well as possible. Academic researchers who are members of the Reflection Group on Integration and Development in Latin America and Europe - GRIDALE participate with their analysis of these challenges of a new world order as a consequence of COVID-19.  Cuando pase la pandemia y sobrevenga la pospandemia, habrá que enfrentar los profundos cambios en el sistema internacional que conducirán hacia un nuevo orden mundial. Dichos cambios cubren diversos frentes: el económico, el geopolítico, el social o el ambiental, y un instrumento como la integración se debe preparar para atender de manera cooperativa, solidaria y consensuada tales retos. En el ámbito económico, se produce una revalorización de la actuación de los Estados mediante políticas públicas orientadas inicialmente de manera prioritaria hacia la salud, pero que derivarán hacia otros temas de política social en materia de empleo y reactivación económica. Así, se consolidarán nuevas formas de encadenamientos productivos y de establecimiento de políticas públicas orientadas a priorizar medidas correspondientes a un Estado de bienestar, donde los objetivos de desarrollo sostenible adquieren prioridad, así como todas las políticas relacionadas con las problemáticas medioambientales. Estas medidas estarán acompañadas de una revalorización del manejo multilateral mediante reformas institucionales y acuerdos globales, influenciados a la vez por una gran disputa del liderazgo mundial entre los Estados Unidos y China, pero en un contexto de regionalización con diferentes áreas del planeta ejerciendo algún papel protagónico, como Asia Oriental y Medio Oriente. Los países de América Latina poco lograrán de manera individual y desorganizada, por lo cual un reto en la pospandemia es reactivar sus procesos de integración para atender las enormes necesidades y requerimientos del mejor modo posible. En este sexto tomo de la colección Gridale, investigadores integrantes del Grupo de Reflexión sobre Integración y Desarrollo en América Latina y Europa (Gridale) analizan los desafíos de un nuevo orden mundial como consecuencia de la COVID-19. 

La COVID-19 y la integración ante los desafíos de un nuevo orden mundial

When the pandemic passes, a fundamental post-pandemic stage comes in which we must face the profound changes in the International System that will lead to a new world order. These changes cover various fronts such as economics and geopolitics, social or environmental, and an instrument such as integration must be prepared to address these challenges in a cooperative, supportive, and consensual manner. In the economicsphere, there is a revaluation of the actions of the States through public policies, initially oriented primarily towards health, but which will lead to other issues of social policy in the field of employment, economic reactivation through new forms of productive chains and of establishing public policies aimed at prioritizing measures corresponding to a Welfare State, where the objectives of sustainable development acquire priority, as well as all the policies related to environmental problems. These measures will be accompanied by a revaluation of multilateral management through institutional reforms and global agreements, influenced at the same time by a great dispute of world leadership between the United States and China, but in a context of regionalization with different areas of the planet playing a leading role, such as East Asia and the Middle East. The countries of Latin America will achieve little individually and in a disorganized manner, which is why a challenge in the post-pandemic is to reactivate their integration processes to meet the enormous needs and requirements that must be addressed as well as possible. Academic researchers who are members of the Reflection Group on Integration and Development in Latin America and Europe - GRIDALE participate with their analysis of these challenges of a new world order as a consequence of COVID-19.  Cuando pase la pandemia y sobrevenga la pospandemia, habrá que enfrentar los profundos cambios en el sistema internacional que conducirán hacia un nuevo orden mundial. Dichos cambios cubren diversos frentes: el económico, el geopolítico, el social o el ambiental, y un instrumento como la integración se debe preparar para atender de manera cooperativa, solidaria y consensuada tales retos. En el ámbito económico, se produce una revalorización de la actuación de los Estados mediante políticas públicas orientadas inicialmente de manera prioritaria hacia la salud, pero que derivarán hacia otros temas de política social en materia de empleo y reactivación económica. Así, se consolidarán nuevas formas de encadenamientos productivos y de establecimiento de políticas públicas orientadas a priorizar medidas correspondientes a un Estado de bienestar, donde los objetivos de desarrollo sostenible adquieren prioridad, así como todas las políticas relacionadas con las problemáticas medioambientales. Estas medidas estarán acompañadas de una revalorización del manejo multilateral mediante reformas institucionales y acuerdos globales, influenciados a la vez por una gran disputa del liderazgo mundial entre los Estados Unidos y China, pero en un contexto de regionalización con diferentes áreas del planeta ejerciendo algún papel protagónico, como Asia Oriental y Medio Oriente. Los países de América Latina poco lograrán de manera individual y desorganizada, por lo cual un reto en la pospandemia es reactivar sus procesos de integración para atender las enormes necesidades y requerimientos del mejor modo posible. En este sexto tomo de la colección Gridale, investigadores integrantes del Grupo de Reflexión sobre Integración y Desarrollo en América Latina y Europa (Gridale) analizan los desafíos de un nuevo orden mundial como consecuencia de la COVID-19. 

La COVID-19 y la integración ante los desafíos de un nuevo orden mundial

When the pandemic passes, a fundamental post-pandemic stage comes in which we must face the profound changes in the International System that will lead to a new world order. These changes cover various fronts such as economics and geopolitics, social or environmental, and an instrument such as integration must be prepared to address these challenges in a cooperative, supportive, and consensual manner. In the economicsphere, there is a revaluation of the actions of the States through public policies, initially oriented primarily towards health, but which will lead to other issues of social policy in the field of employment, economic reactivation through new forms of productive chains and of establishing public policies aimed at prioritizing measures corresponding to a Welfare State, where the objectives of sustainable development acquire priority, as well as all the policies related to environmental problems. These measures will be accompanied by a revaluation of multilateral management through institutional reforms and global agreements, influenced at the same time by a great dispute of world leadership between the United States and China, but in a context of regionalization with different areas of the planet playing a leading role, such as East Asia and the Middle East. The countries of Latin America will achieve little individually and in a disorganized manner, which is why a challenge in the post-pandemic is to reactivate their integration processes to meet the enormous needs and requirements that must be addressed as well as possible. Academic researchers who are members of the Reflection Group on Integration and Development in Latin America and Europe - GRIDALE participate with their analysis of these challenges of a new world order as a consequence of COVID-19.  Cuando pase la pandemia y sobrevenga la pospandemia, habrá que enfrentar los profundos cambios en el sistema internacional que conducirán hacia un nuevo orden mundial. Dichos cambios cubren diversos frentes: el económico, el geopolítico, el social o el ambiental, y un instrumento como la integración se debe preparar para atender de manera cooperativa, solidaria y consensuada tales retos. En el ámbito económico, se produce una revalorización de la actuación de los Estados mediante políticas públicas orientadas inicialmente de manera prioritaria hacia la salud, pero que derivarán hacia otros temas de política social en materia de empleo y reactivación económica. Así, se consolidarán nuevas formas de encadenamientos productivos y de establecimiento de políticas públicas orientadas a priorizar medidas correspondientes a un Estado de bienestar, donde los objetivos de desarrollo sostenible adquieren prioridad, así como todas las políticas relacionadas con las problemáticas medioambientales. Estas medidas estarán acompañadas de una revalorización del manejo multilateral mediante reformas institucionales y acuerdos globales, influenciados a la vez por una gran disputa del liderazgo mundial entre los Estados Unidos y China, pero en un contexto de regionalización con diferentes áreas del planeta ejerciendo algún papel protagónico, como Asia Oriental y Medio Oriente. Los países de América Latina poco lograrán de manera individual y desorganizada, por lo cual un reto en la pospandemia es reactivar sus procesos de integración para atender las enormes necesidades y requerimientos del mejor modo posible. En este sexto tomo de la colección Gridale, investigadores integrantes del Grupo de Reflexión sobre Integración y Desarrollo en América Latina y Europa (Gridale) analizan los desafíos de un nuevo orden mundial como consecuencia de la COVID-19.