Sistema especialista para o domínio do Licenciamento Ambiental: estudo de caso com Shell Expert Sinta/ Specialist system for the domain of Environmental Licensing: case study with Shell Expert Sinta

Este documento busca relatar o processo de modelagem e a construção de um protótipo de sistema especialista no domínio do licenciamento ambiental, com a utilização do Shell Expert Sinta utilizando técnicas de inteligência artificial. Apresenta uma seção inicial com aspectos do campo da Inteligência Artificial, Sistemas Especialistas, do Shell Expert SINTA e a delimitação do Licenciamento Ambiental, em seguida os materiais e métodos do processo de modelagem e construção do protótipo e as conclusões e considerações acerca da pesquisa. Os sistemas baseados em conhecimento são o objeto deste estudo, através da modelagem e construção de um sistema especialista no domínio do Licenciamento Ambiental, quanto às ações executadas por Órgãos Públicos Estaduais, especificamente no enquadramento dos empreendimentos licenciáveis no âmbito da gestão do meio ambiente

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants.

BACKGROUND: Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. METHODS: We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. FINDINGS: The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. INTERPRETATION: Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings. FUNDING: WHO

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30-79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30-79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306-359) million women and 317 (292-344) million men in 1990 to 626 (584-668) million women and 652 (604-698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55-62) of women and 49% (46-52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43-51) of women and 38% (35-41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20-27) for women and 18% (16-21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings. Copyright (C) 2021 World Health Organization; licensee Elsevier

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings

Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants

Background Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories. Methods We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age. Findings The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran. Interpretation Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings

A rigorous architectural approach to development component-based software systems

Orientador: Cecília Mary Fischer RubiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: A incorporação de tolerância a falhas em sistemas de software normalmente acarreta em um aumento da complexidade, o que consequentemente torna a sua análise mais difícil. Além disso, o uso de mecanismos de tratamento de exceções de uma maneira não-sistemática pode acarretar na adição de novas falhas ao sistema. Esta tese apresenta uma abordagem rigorosa e centrada na arquitetura para o desenvolvimento de sistemas de software tolerantes a falhas. Dependendo do modelo de falhas e da disponibilidade de recursos, abstrações arquiteturais diferentes podem ser utilizadas para representar explicitamente questões relacionadas a tolerância a falhas, tais como detecção e tratamento de erros e tratamento de falhas. Essas abstrações arquiteturais e os seus respectivos detalhamentos internos podem ser instanciados em componentes e conectores concretos durante o projeto de arquiteturas de software tolerantes a falhas. De forma complementar, a solução proposta também define atividades que combinam o uso e métodos formais e casos de teste baseados em modelos para sistematizar a verificação e validação do comportamento do sistema relativo à programação e tratamento de erros e tratamento de falhas no nível arquitetural. A verificação e validação de software ocorrem em duas fases complementares do processo de desenvolvimento do software, ambas baseadas em cenários arquiteturais que descrevem a programação e tratamento de erros envolvendo elementos arquiteturais (componentes e conectores). Primeiramente, utilizando a ferramenta de verificação de modelos ProB, que combina o uso de teoria de conjuntos matemáticos (B-Method) com álgebra de processos (CSP), a arquitetura de software é verificada formalmente com o intuito de antecipar a identificação de falhas relacionadas ao projeto do sistema. Segundo, casos de teste são gerados a partir da arquitetura de software utilizando uma abordagem baseada em modelos. O objetivo dos casos de teste gerados é verificar a consistência entre os modelos arquiteturais já verificados formalmente e a implementação do sistema. Finalmente, para auxiliar as atividades de verificação, a solução proposta também contempla a definição de regras de transformação automática de diagramas UML para especificação formal em B-Method e CSP. A diferença semântica existe entre a especificação semi-formal da UML e a especificação formal em B-Method e CSP é compensada utilizando-se estereótipos e "tags" nos modelos UML. A aplicabilidade prática da solução proposta foi avaliada no contexto de três estudos de caso: (i) uma aplicação com requisitos críticos de tempo real e confiabilidade; (ii) uma aplicação bancária real com requisitos críticos de confiabilidade e disponibilidades; e (iii) uma aplicação para dispositivos móveisAbstract: The incorporation of fault tolerance into systems normally increases their complexity, which consequently makes their analysis more difficult. Moreover, the use of exception handling mechanisms to develop robust software systems in a non-systematic manner can be a source of many design faults. This thesis presents a rigorous and architecture-centric development approach for developing fault-tolerant software systems. Depending on the fault model and the resources available, different architectural abstractions can be employed for representing issues that are related to fault tolerance, such as error detection, and error and fault handling. These architectural abstractions and their internal views can be instantiated into concrete components and connectors for designing fault-tolerant software architectures. In a complementary way, the proposed rigorous solution also defines activities which use formal methods and model-based test cases do systematize the verification and validation of the system's behaviour related to error propagation and handling at the architecture level. The verification and validation occur in two complementary phases of the software development, both of them based on architectural scenarios describing error propagation and handling involving architectural elements (components and connectors). First, using the ProB model checker, which combines the use of set-theory (B-Method) and process algebra (CSP), the software architecture is formally verified in order to anticipate the identification of faults related to the system's model. Second, model-based test cases are generated in order to assess the consistency between the verified software architecture and the implementation of the software system. Finally, the proposed solution also defines rules for model transformation from UML diagrams to formal specification in B-Method and CSP. To overcome the gap between the semi-formal specification of UML and the formal models, the UML diagrams are complemented with predefined stereotypes and tags. The feasibility of our approach was evaluated in the context of three case studies: (i) a critical real-time application; (ii) a real banking system; and (iii) a mobile applicationDoutoradoEngenharia de SoftwareDoutor em Ciência da Computaçã

A method for modelling exceptions in component-based software development

Orientador: Cecilia Mary Fischer RubiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Devido a grande popularização do Desenvolvimento Baseado em Componentes (DBC), ele vem sendo empregado inclusive no desenvolvimento de sistemas computacionais críticos. O emprego do DBC na construção de sistemas confiáveis evidencia a necessidade de se desenvolver componentes de software que sejam robustos e que possuam uma garantia maior do seu funcionamento correto. Tratamento de exceções é uma técnica bastante conhecida para a verificação e tratamento de erros em sistemas de software. Por'em, apesar da sua popularidade, o seu projeto e a implementação são constituídos de tarefas muito complexas que não recebem uma atenção adequada dos processos de desenvolvimento existentes. A situação É ainda mais crítica se levarmos em considera¸c¿ao os métodos para DBC. Este trabalho propõe um método para auxiliar a modelagem do comportamento excepcional de sistemas baseados em componentes, chamado MDCE+. Baseado no refinamento da metodologia MDCE, o MDCE+ apresenta dois diferenciais importantes, que reforçam o seu aspecto robusto: (i) o fato dele combinar as abordagens top-down e botton-up para o desenvolvimento de sistemas confiáveis; e (ii) o fato dele ser centrado na arquitetura. O foco na arquitetura de software contribui para uma melhor definição e análise do fluxo de exceções entre os componentes do sistema. Essa maneira estruturada de detectar e tratar exceções no contexto da ocorrência de falhas é particularmente relevante para sistemas que apresentam requisitos de confiabilidade extrema. O método MDCE+ é um método genérico que pode ser aplicada a processos de desenvolvimento modernos. Em particular, nesta dissertação o método MDCE+ foi adaptado ao processo UML Components e a uma metodologia de testes. Como maneira de avaliar esse método, foi desenvolvido um estudo de caso de um sistema financeiro real, com requisitos de tolerância a falhas. Dada a sua importância, o processo de avaliação do método MDCE+ foi dividido em tr¿es etapas: (i) preparação; (ii) execução; e (iii) análise dos resultados. Nesse estudo foi necessário tratar exceções na arquitetura do sistema, com o intuito de aumentar a disponibilidade dos serviçosAbstract: Due to the large adoption of the Component-Based Development (CBD), it has also been employed in the development of critical software systems. The development of dependable systems using the CBD paradigm evidences the necessity of developing software components that are robust and dependable. Exception handling is a well known technique for verify and treat errors in software systems. However, despite its popularity, its design and implementation are constituted of very complex tasks that do not receive the adequate attention from the existing development processes. This is still more critical in the context of CBD processes. This work presents the MDCE+, a method that assists the modeling of the exceptional behavior in component-based software development. Based in the refinement of the MDCE methodology, the MDCE+ presents two important differentials, that strengthen its robustness: (i) it combines the top-down and bottom-up strategies for the development of dependable systems; and (ii) it is centered in the software architecture. As a consequence of the focus given to the software architecture, the exceptions that flow between the system components are better defined and analyzed. This structured way to detect and to treat exceptions in the context of the occurrence of imperfections is particularly needed for developing dependable systems. The MDCE+ is a generic method that can be applied together with modern development processes. In particular, in this master thesis MDCE+ was adapted to the UML Components process and to a software test methodology. In order to evaluate this method, a case study of a real financial system with fault-tolerance requirements was developed. Given its importance, the evaluation process of the MDCE+ method was decomposed in three stages: (i) preparation; (ii) execution; and (iii) results analysis. In order to increase the services availability, in this study it was necessary to deal with exceptions in the software architectureMestradoEngenharia de SoftwareMestre em Ciência da Computaçã

Verification of Exception Control Flows and Handlers Based on Architectural Scenarios

The use of exception handling mechanisms to develop robust software systems in a non-systematic manner can be a source of many design faults. This paper presents a rigorous development approach based on formal methods, which allows to systematise the verification of the system's abnormal behaviour at the architectural level. Our solution is based on the specification and verification of architectural scenarios, which describe both exception control flows and exception handlers involving architectural elements (components and connectors). We also adopt an architectural abstraction for guiding the internal structure of the architectural elements. The verification process is conducted using the ProB model checker, which combines the use of set-theory (B-Method) and a process algebra (CSP). The feasibility of our approach was evaluated by a case study from the financial domain

Designing fault-tolerant SOA based on design diversity.

Background: Over recent years, software developers have been evaluating the benefits of both Service-Oriented Architecture (SOA) and software fault tolerance techniques based on design diversity. This is achieved by creating fault-tolerant composite services that leverage functionally-equivalent services. Three major design issues need to be considered while building software fault-tolerant architectures based on design diversity: (i) selection of variants; (ii) selection of an adjudication algorithm to choose one of the results; and (iii) execution of variants. In addition, applications based on SOA need to function effectively in a dynamic environment where it is necessary to postpone decisions until runtime. In this scenario, control is highly distributed and involves conflicting user requirements. We aim to support the software architect in the design of fault-tolerant compositions. Methods: Leveraging a taxonomy for fault-tolerant systems, this paper proposes guidelines to aid software architects in making key design decisions. The taxonomy is used as the basis for defining a set of guidelines to support the architect in making decisions related to fault tolerance in SOA. The same taxonomy is used in a systematic literature review of solutions for fault-tolerant composite services. The review investigates how existing approaches for fault-tolerant composite services address design diversity issues and also specific issues related to SOA. Results: The contribution of this work is twofold: (i) a set of guidelines for supporting the design of fault-tolerant SOA, based on a taxonomy for fault tolerance techniques; and (ii) a systematic literature review of existing solutions for designing fault-tolerant compositions using design diversity. Conclusion: Although existing solutions have made significant contributions to the development of fault-tolerant SOAs, there is a lack of approaches for fault-tolerant service composition that support strategies with diverse quality requirements and encompassing sophisticated context-aware capabilities. This paper discusses which design issues have been addressed by existing diversity-based approaches for fault-tolerant composite services. Finally, practical issues and difficulties are summarized and directions for future work are suggested