Nuvens de infraestrutura como serviço (IaaS) estão se tornando um ambiente habitual para execução de aplicações modernas da Internet. Muitas plataformas de gerenciamento de nuvem estão disponíveis para aquele que deseja construir uma nuvem de IaaS privada ou pública (e.g., OpenStack, Eucalyptus, OpenNebula). Um aspecto comum do projeto de plataformas atuais diz respeito ao seu modelo de controle caixa-preta. Em geral, as plataformas de gerenciamento de nuvem são distribuídas com um conjunto de estratégias de alocação de recursos embutida em seu núcleo. Dessa forma, os administradores de nuvem têm poucas oportunidades de influenciar a maneira como os recursos são realmente gerenciados (e.g., posicionamento de máquinas virtuais ou seleção caminho de enlaces virtuais). Os administradores poderiam se beneficiar de personalizações em estratégias de gerenciamento de recursos, por exemplo, para atingir os objetivos específicos de cada ambiente ou a fim de permitir a alocação de recursos orientada à aplicação. Além disso, as preocupações acerca do gerenciamento de recursos em nuvens se dividem geralmente em computação, armazenamento e redes. Idealmente, essas três preocupações deveriam ser abordadas no mesmo nível de importância por implementações de plataformas. No entanto, ao contrário do gerenciamento de computação e armazenamento, que têm sido amplamente estudados, o gerenciamento de redes em ambientes de nuvem ainda é bastante incipiente. A falta de flexibilidade e suporte desequilibrado para o gerenciamento de recursos dificulta a adoção de nuvens como um ambiente de execução viável para muitas aplicações modernas da Internet com requisitos rigorosos de elasticidade e qualidade do serviço. Nesta tese, um novo conceito de plataforma de gerenciamento de nuvem é introduzido onde o gerenciamento de recursos flexível é obtido pela adição de programabilidade no núcleo da plataforma. Além disso, uma API simplificada e orientada a objetos é introduzida a fim de permitir que os administradores escrevam e executem programas de gerenciamento de recursos para lidar com todos os tipos de recursos a partir de um único ponto. Uma plataforma é apresentada como uma prova de conceito, incluindo um conjunto de adaptadores para lidar com tecnologias de virtualização e de redes modernas, como redes definidas por software com OpenFlow, Open vSwitches e Libvirt. Dois estudos de caso foram realizados a fim de avaliar a utilização de programas de gerenciamento de recursos para implantação e otimização de aplicações através de uma rede emulada usando contêineres de virtualização Linux e Open vSwitches operando sob o protocolo OpenFlow. Os resultados mostram a viabilidade da abordagem proposta e como os programas de implantação e otimização são capazes de alcançar diferentes objetivos definidos pelo administrador. / Infrastructure as a Service (IaaS) clouds are becoming an increasingly common way to deploy modern Internet applications. Many cloud management platforms are available for users that want to build a private or public IaaS cloud (e.g., OpenStack, Eucalyptus, OpenNebula). A common design aspect of current platforms is their black-box-like controlling nature. In general, cloud management platforms ship with one or a set of resource allocation strategies hard-coded into their core. Thus, cloud administrators have few opportunities to influence how resources are actually managed (e.g., virtual machine placement or virtual link path selection). Administrators could benefit from customizations in resource management strategies, for example, to achieve environment specific objectives or to enable application-oriented resource allocation. Furthermore, resource management concerns in clouds are generally divided into computing, storage, and networking. Ideally, these three concerns should be addressed at the same level of importance by platform implementations. However, as opposed to computing and storage management, which have been extensively investigated, network management in cloud environments is rather incipient. The lack of flexibility and unbalanced support for resource management hinders the adoption of clouds as a viable execution environment for many modern Internet applications with strict requirements for elasticity or Quality of Service. In this thesis, a new concept of cloud management platform is introduced where resource management is made flexible by the addition of programmability to the core of the platform. Moreover, a simplified object-oriented API is introduced to enable administrators to write and run resource management programs to handle all kinds of resources from a single point. An implementation is presented as a proof of concept, including a set of drivers to deal with modern virtualization and networking technologies, such as software-defined networking with OpenFlow, Open vSwitches, and Libvirt. Two case studies are conducted to evaluate the use of resource management programs for the deployment and optimization of applications over an emulated network using Linux virtualization containers and Open vSwitches running the OpenFlow protocol. Results show the feasibility of the proposed approach and how deployment and optimization programs are able to achieve different objectives defined by the administrator.

Computação em nuvem é uma solução adequada para profissionais, empresas, centros de pesquisa e instituições que necessitam de acesso a recursos computacionais sob demanda. Atualmente, nuvens computacionais confiam no gerenciamento de sua estrutura para fornecer recursos computacionais com qualidade de serviço adequada as expectativas de seus clientes, tal qualidade de serviço é estabelecida através de acordos de nível de serviço. Nesse contexto, o monitoramento é uma função crítica de gerenciamento para se prover tal qualidade de serviço. Requisitos de monitoramento em nuvens computacionais são propriedades que um sistema de monitoramento de nuvem precisa reunir para executar suas funções de modo adequado e atualmente existem diversos requisitos definidos pela literatura, tais como: oportunidade, elasticidade e escalabilidade. Entretanto, tais requisitos geralmente possuem influência mútua entre eles, que pode ser positiva ou negativa, e isso impossibilita o desenvolvimento de soluções de monitoramento completas. Dado o cenario descrito acima, essa tese tem como objetivo investigar a influência mútua entre escalabilidade e oportunidade. Especificamente, essa tese propõe um modelo matemático para estimar a influência mútua entre tais requisitos de monitoramento. A metodologia utilizada por essa tese para construir tal modelo matemático baseia-se em parâmetros de monitoramento tais como: topologia de monitoramento, quantidade de dados de monitoramento e frequencia de amostragem. Além destes, a largura de banda de rede e o tempo de resposta também são importantes métricas do modelo matemático. A avaliação dos resultados obtidos foi realizada através da comparação entre os resultados do modelo matemático e de uma simulação. As maiores contribuições dessa tese são divididas em dois eixos, estes são denominados: Básico e Chave. As contribuições do eixo básico são: (i) a discussão a respeito da estrutura de monitoramento de nuvem e introdução do conceito de foco de monitoramento (ii) o exame do conceito de requisito de monitoramento e a proposição do conceito de abilidade de monitoramento (iii) a análise dos desafios e tendências a respeito de monitoramento de nuvens computacionais. As contribuições do eixo chave são: (i) a discussão a respeito de oportunidade e escalabilidade incluindo métodos para lidar com a mútua influência entre tais requisitos e a relação desses requisitos com parâmetros de monitoramento (ii) a identificação dos parâmetros de monitoramento que são essenciais na relação entre oportunidade e escalabilidade (iii) a proposição de um modelo matemático baseado em parâmetros de monitoramento que visa estimar a relação mútua entre oportunidade e escalabilidade. / Cloud computing is a suitable solution for professionals, companies, research centres, and institutions that need to have access to computational resources on demand. Nowadays, clouds have to rely on proper management of its structure to provide such computational resources with adequate quality of service, which is established by Service Level Agreements (SLAs), to customers. In this context, cloud monitoring is a critical management function to achieve it. Cloud monitoring requirements are properties that a cloud monitoring system need to meet to perform its functions properly, and currently there are several of them such as timeliness, elasticity and scalability. However, such requirements usually have mutual influence, which is either positive or negative, among themselves, and it has prevented the development of complete cloud monitoring solutions. From the above, this thesis investigates the mutual influence between timeliness and scalability. This thesis proposes a mathematical model to estimate such mutual influence to enhance cloud monitoring systems. The methodology used in this thesis is based on monitoring parameters such as monitoring topologies, the amount of monitoring data, and frequency sampling. Besides, it considers as important metrics network bandwidth and response time. Finally, the evaluation is based on a comparison of the mathematical model results and outcomes obtained via simulation. The main contributions of this thesis are divided into two axes, namely, basic and key. Basic contributions of this thesis are: (i) it discusses the cloud monitoring structure and introduced the concept of cloud monitoring focus (ii) it examines the concept of cloud monitoring requirement and proposed to divide them into two groups defined as cloud monitoring requirements and cloud monitoring abilities (iii) it analysed challenges and trends in cloud monitoring pointing research gaps that include the mutual influence between cloud monitoring requirements which is core to the key contributions. The key contributions of this thesis are: (i) it presents a discussion of timeliness and scalability that include: the methods currently used to cope with the mutual influence between them, and the relation between such requirements and monitoring parameters (ii) it identifies the monitoring parameters that are essential in the relation between timeliness and scalability (iii) it proposes a mathematical model based on monitoring parameters to estimate the mutual influence between timeliness and scalability.

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L'usage des plateformes de Cloud Computing offrant une Infrastructure en tant que service (IaaS) a augmenté au sein de l'industrie. Les infrastructures IaaS fournissent des ressources virtuelles depuis un catalogue de types prédéfinis. Les avancées dans le domaine de la virtualisation rendent possible la création et la destruction de machines virtuelles au fur et à mesure, avec un faible surcout d'exploitation. En conséquence, le bénéfice offert par les plate-formes IaaS est la possibilité de dimensionner une architecture virtuelle au fur et à mesure de l'utilisation, et de payer uniquement les ressources utilisées. D'un point de vue scientifique, les plateformes IaaS soulèvent de nouvelles questions concernant l'efficacité des décisions prises en terme de passage à l'échelle, et également l'ordonnancement des applications sur les plateformes dynamiques. Les travaux de cette thèse explorent ce thème et proposent des solutions à ces deux problématiques. La première contribution décrite dans cette thèse concerne la gestion des ressources. Nous avons travaillé sur le redimensionnement automatique des applications clientes de Cloud afin de modéliser les variations d'utilisation de la plateforme. De nombreuses études ont montré des autosimilarités dans le trafic web des plateformes, ce qui implique l'existence de motifs répétitifs pouvant être périodiques ou non. Nous avons développé une stratégie automatique de dimensionnement, capable de prédire le temps d'utilisation de la plateforme en identifiant les motifs répétitifs non périodiques. Dans un second temps, nous avons proposé d'étendre les fonctionnalités d'un intergiciel de grilles, en implémentant une utilisation des ressources à la demandes.Nous avons développé une extension pour l'intergiciel DIET (Distributed Interactive Engineering Toolkit), qui utilise un marché virtuel pour gérer l'allocation des ressources. Chaque utilisateur se voit attribué un montant de monnaie virtuelle qu'il utilisera pour exécuter ses tâches. Le mécanisme d'aide assure un partage équitable des ressources de la plateforme entre les différents utilisateurs. La troisième et dernière contribution vise la gestion d'applications pour les plateformes IaaS. Nous avons étudié et développé une stratégie d'allocation des ressources pour les applications de type workflow avec des contraintes budgétaires. L'abstraction des applications de type workflow est très fréquente au sein des applications scientifiques, dans des domaines variés allant de la géologie à la bioinformatique. Dans ces travaux, nous avons considéré un modèle général d'applications de type workflow qui contient des tâches parallèles et permet des transitions non déterministes. Nous avons élaboré deux stratégies d'allocations à contraintes budgétaires pour ce type d'applications. Le problème est une optimisation à deux critères dans la mesure où nous optimisons le budget et le temps total du flux d'opérations. Ces travaux ont été validés de façon expérimentale par leurs implémentations au sein de la plateforme de Cloud libre Nimbus et de moteur de workflow MADAG présent au sein de DIET. Les tests ont été effectuées sur une simulation de cosmologie appelée RAMSES. RAMSES est une application parallèle qui, dans le cadre de ces travaux, a été portée sur des plateformes virtuelles dynamiques. L'ensemble des résultats théoriques et pratiques ont débouché sur des résultats encourageants et des améliorations. / Infrastructure as a service (IaaS) Cloud platforms are increasingly used in the IT industry. IaaS platforms are providers of virtual resources from a catalogue of predefined types. Improvements in virtualization technology make it possible to create and destroy virtual machines on the fly, with a low overhead. As a result, the great benefit of IaaS platforms is the ability to scale a virtual platform on the fly, while only paying for the used resources. From a research point of view, IaaS platforms raise new questions in terms of making efficient virtual platform scaling decisions and then efficiently scheduling applications on dynamic platforms. The current thesis is a step forward towards exploring and answering these questions. The first contribution of the current work is focused on resource management. We have worked on the topic of automatically scaling cloud client applications to meet changing platform usage. There have been various studies showing self-similarities in web platform traffic which implies the existence of usage patterns that may or may not be periodical. We have developed an automatic platform scaling strategy that predicted platform usage by identifying non-periodic usage patterns and extrapolating future platform usage based on them. Next we have focused on extending an existing grid platform with on-demand resources from an IaaS platform. We have developed an extension to the DIET (Distributed Interactive Engineering Toolkit) middleware, that uses a virtual market based approach to perform resource allocation. Each user is given a sum of virtual currency that he will use for running his tasks. This mechanism help in ensuring fair platform sharing between users. The third and final contribution targets application management for IaaS platforms. We have studied and developed an allocation strategy for budget-constrained workflow applications that target IaaS Cloud platforms. The workflow abstraction is very common amongst scientific applications. It is easy to find examples in any field from bioinformatics to geology. In this work we have considered a general model of workflow applications that comprise parallel tasks and permit non-deterministic transitions. We have elaborated two budget-constrained allocation strategies for this type of workflow. The problem is a bi-criteria optimization problem as we are optimizing both budget and workflow makespan. This work has been practically validated by implementing it on top of the Nimbus open source cloud platform and the DIET MADAG workflow engine. This is being tested with a cosmological simulation workflow application called RAMSES. This is a parallel MPI application that, as part of this work, has been ported for execution on dynamic virtual platforms. Both theoretical simulations and practical experiments have shown encouraging results and improvements.

Cloud computing is an emerging model in which applications, data, computing resources and operating platforms are provided to clients as a service. It represents a unique way to architect and remotely manage computing resources with minimal management effort or service provider interaction. As it become widely used and being relayed on, security and the risks surrounding it became more in focus to ensure the data protection. The purpose of the study is to focus on the security risks of confidentiality, integrity and availability, and how the cloud consumer perceives cloud security based on those risks. For this purpose, a qualitative research method was adopted and semi-structured interviews with 6 users with experience within the cloud were conducted to collect the data. The data were analysed and explained using codes and categories, based on the research questions and related literature. A roadmap was developed consist of four elements which can support in the migration decision. Those elements are: Trust, Compliance, Proactive and Continuous assessment.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Os dispositivos mÃveis, especificamente os smartphones e os tablets, evoluÃram bastante em termos computacionais nos Ãltimos anos, e estÃo cada vez mais presentes no cotidiano das pessoas. Apesar dos avanÃos tecnolÃgicos, a principal limitaÃÃo desses dispositivos està relacionada com a questÃo energÃtica e com seu baixo desempenho computacional, quando comparado com um notebook ou computador de mesa. Com base nesse contexto, surgiu o paradigma do Mobile Cloud Computing (MCC), o qual estuda formas de estender os recursos computacionais e energÃticos dos dispositivos mÃveis atravÃs da utilizaÃÃo das tÃcnicas de offloading. A partir do levantamento bibliogrÃfico dos frameworks em MCC verificou-se, para o problema da heterogeneidade em plataformas mÃveis, ausÃncia de soluÃÃes de offloading. Diante deste problema, esta dissertaÃÃo apresenta um framework denominado de MpOS (Multiplataform Offloading System), que suporta a tÃcnica de offloading, em relaÃÃo ao desenvolvimento de aplicaÃÃes para diferentes plataformas mÃveis, sendo desenvolvido inicialmente para as plataformas Android e Windows Phone. Para validaÃÃo foram desenvolvidas para cada plataforma mÃvel, duas aplicaÃÃes mÃveis, denominadas de BenchImage e Collision, que demonstram o funcionamento da tÃcnica de offloading em diversos cenÃrios. No caso do experimento realizado com BenchImage foi analisado o desempenho da aplicaÃÃo mÃvel, em relaÃÃo à execuÃÃo local, no cloudlet server e em uma nuvem pÃblica na Internet, enquanto no experimento do Collision (um aplicativo de tempo real) foi analisado o desempenho do offloading, utilizando tambÃm diferentes sistemas de serializaÃÃo de dados. Em ambos os experimentos houve situaÃÃes que era mais vantajoso executar localmente no smartphone, do que realizar a operaÃÃo de offloading e vice-versa, por causa de diversos fatores associados com a qualidade da rede e com volume de processamento exigido nesta operaÃÃo. / The mobile devices, like smartphones and tablets, have evolved considerably in last years in computational terms. Despite advances in their hardware, these devices have energy constraints regarded to their poor computing performance. Therefore, on this context, a new paradigm called Mobile Cloud Computing (MCC) has emerged. MCC studies new ways to extend the computational and energy resources, on mobile devices using the offloading techniques. A literature survey about MCC, has shown that there is no support heterogeneity on reported studies. In response, we propose a framework called MpOS (Multi-platform Offloading System), which supports the offloading technique in mobile application development, for two mobile platforms (Android and Windows Phone). Two case studies were developed with MpOS solution in order to evaluate the framework for each mobile platform. These case studies show how the offloading technique works on several perspectives. In BenchImage experiment, the offloading performance was analyzed, concerning to its execution on a remote execution site (a cloudlet on local network and public cloud in the Internet). The Collision application promotes the analysis of the offloading technique performance on real-time application, also using different serialization systems. In both experiments, results show some situations where it was better to run locally on smarphone, than performing the offloading operation and vice versa.

Nuvens de infraestrutura como serviço (IaaS) estão se tornando um ambiente habitual para execução de aplicações modernas da Internet. Muitas plataformas de gerenciamento de nuvem estão disponíveis para aquele que deseja construir uma nuvem de IaaS privada ou pública (e.g., OpenStack, Eucalyptus, OpenNebula). Um aspecto comum do projeto de plataformas atuais diz respeito ao seu modelo de controle caixa-preta. Em geral, as plataformas de gerenciamento de nuvem são distribuídas com um conjunto de estratégias de alocação de recursos embutida em seu núcleo. Dessa forma, os administradores de nuvem têm poucas oportunidades de influenciar a maneira como os recursos são realmente gerenciados (e.g., posicionamento de máquinas virtuais ou seleção caminho de enlaces virtuais). Os administradores poderiam se beneficiar de personalizações em estratégias de gerenciamento de recursos, por exemplo, para atingir os objetivos específicos de cada ambiente ou a fim de permitir a alocação de recursos orientada à aplicação. Além disso, as preocupações acerca do gerenciamento de recursos em nuvens se dividem geralmente em computação, armazenamento e redes. Idealmente, essas três preocupações deveriam ser abordadas no mesmo nível de importância por implementações de plataformas. No entanto, ao contrário do gerenciamento de computação e armazenamento, que têm sido amplamente estudados, o gerenciamento de redes em ambientes de nuvem ainda é bastante incipiente. A falta de flexibilidade e suporte desequilibrado para o gerenciamento de recursos dificulta a adoção de nuvens como um ambiente de execução viável para muitas aplicações modernas da Internet com requisitos rigorosos de elasticidade e qualidade do serviço. Nesta tese, um novo conceito de plataforma de gerenciamento de nuvem é introduzido onde o gerenciamento de recursos flexível é obtido pela adição de programabilidade no núcleo da plataforma. Além disso, uma API simplificada e orientada a objetos é introduzida a fim de permitir que os administradores escrevam e executem programas de gerenciamento de recursos para lidar com todos os tipos de recursos a partir de um único ponto. Uma plataforma é apresentada como uma prova de conceito, incluindo um conjunto de adaptadores para lidar com tecnologias de virtualização e de redes modernas, como redes definidas por software com OpenFlow, Open vSwitches e Libvirt. Dois estudos de caso foram realizados a fim de avaliar a utilização de programas de gerenciamento de recursos para implantação e otimização de aplicações através de uma rede emulada usando contêineres de virtualização Linux e Open vSwitches operando sob o protocolo OpenFlow. Os resultados mostram a viabilidade da abordagem proposta e como os programas de implantação e otimização são capazes de alcançar diferentes objetivos definidos pelo administrador. / Infrastructure as a Service (IaaS) clouds are becoming an increasingly common way to deploy modern Internet applications. Many cloud management platforms are available for users that want to build a private or public IaaS cloud (e.g., OpenStack, Eucalyptus, OpenNebula). A common design aspect of current platforms is their black-box-like controlling nature. In general, cloud management platforms ship with one or a set of resource allocation strategies hard-coded into their core. Thus, cloud administrators have few opportunities to influence how resources are actually managed (e.g., virtual machine placement or virtual link path selection). Administrators could benefit from customizations in resource management strategies, for example, to achieve environment specific objectives or to enable application-oriented resource allocation. Furthermore, resource management concerns in clouds are generally divided into computing, storage, and networking. Ideally, these three concerns should be addressed at the same level of importance by platform implementations. However, as opposed to computing and storage management, which have been extensively investigated, network management in cloud environments is rather incipient. The lack of flexibility and unbalanced support for resource management hinders the adoption of clouds as a viable execution environment for many modern Internet applications with strict requirements for elasticity or Quality of Service. In this thesis, a new concept of cloud management platform is introduced where resource management is made flexible by the addition of programmability to the core of the platform. Moreover, a simplified object-oriented API is introduced to enable administrators to write and run resource management programs to handle all kinds of resources from a single point. An implementation is presented as a proof of concept, including a set of drivers to deal with modern virtualization and networking technologies, such as software-defined networking with OpenFlow, Open vSwitches, and Libvirt. Two case studies are conducted to evaluate the use of resource management programs for the deployment and optimization of applications over an emulated network using Linux virtualization containers and Open vSwitches running the OpenFlow protocol. Results show the feasibility of the proposed approach and how deployment and optimization programs are able to achieve different objectives defined by the administrator.

A história dos sistemas ERP tem início nos anos 90 com sua adoção por grandes corporações. Seu uso tem se intensificado, bem como suas funcionalidades complementares, com o objetivo de integrar os processos de gestão da empresa dentro e fora do espaço físico tradicional. Já sua adoção pelas organizações tem sido alavancada com objetivo de redução de custos, mas, justamente o custo de sua implantação tem sido um limitador. A possibilidade de utilização do ERP em cloud computing se mostra uma alternativa viável, pois reduz uma série de custos da implantação. No entanto, a implantação do ERP em cloud computing traz influências sobre o formato em que o ERP é implantado, bem como modifica os fatores relevantes (críticos para o sucesso) da sua implantação e utilização. Este trabalho analisa os fatores críticos de sucesso existentes na literatura atual e como estes foram relevantes em implantações feitas em cloud computing nas 3 empresas estudadas. Trata-se então de um estudo de casos realizado a partir de um roteiro de entrevistas, aplicado aos responsáveis pela implantação interna e externamente em três empresas brasileiras de ramos de atuação e sistemas implantados diferentes. Este trabalho apresenta conceitos relacionados aos sistemas ERP e os fatores críticos de sucesso disponíveis na literatura, bem como uma caracterização deste novo ambiente de cloud computing e a relação existente com implantações de ERP já registrados. A partir destes resultados outros estudos podem acompanhar a evolução de cloud computing ligado ao ERP ou a partir de uma base instalada maior, segmentar as análises e até mesmo consolidar metodologias de implantação para este novo formato. Por se tratar de um estudo de caso, as conclusões não podem ser generalizadas para todas as organizações, além disso, a existência de poucos fornecedores e poucas implantações de ERP no formato cloud computing, tratando-se de uma tecnologia muito recente, conferem outra limitação para este estudo. / The history of ERP\'s systems starts in 90 years with the adoption by large corporations. Its use has intensified since then as well as additional features, in order to integrate the company\'s management processes within and outside the traditional physical space. Since its adoption by organizations have been leveraged in order to reduce costs, but, just the cost of its implementation has been a limiter. The usability of ERP on cloud computing proves a viable alternative because it reduces a number of deployment costs. However, the implementation of ERP in cloud computing brings influences on the format in which the ERP is implemented, as well as modify the relevant factors (critical success) of their deployment and use. This paper analyzes the critical success factors in the existing literature and how these were relevant in cloud computing deployments made in 3 companies studied. It is then a case study carried out from a set of interviews applied to those responsible for implementing internally and externally in three Brazilian companies midsize segments of operation and different systems deployed. This paper presents concepts related to ERP systems and the critical success factors available in the literature, as well as a characterization of this new cloud computing environment and the relationship with existing ERP implementations already registered. From these results, other studies may follow the evolution of cloud computing ERP connected to or from a larger installed base, segment analysis and even consolidate deployment methodologies for this new format. Because it is a case study, the findings can\'t be generalized to all organizations, moreover, that there are few suppliers and few ERP implementations in the format cloud computing, as it is a very recent technology, provide another limitation for this study.

Cloud computing has become a significant and well-known term within a short period of time. Some parts of it might even be considered as unclear, including its vague definition. Cloud computing has rapidly and successfully come to perform an essential role within information technology and therefore in how organizations are managing their IT departments today. Its many advantages allure organizations to deploy a cloud solution. Despite the flourishing growth of cloud computing it still has its draw backs. One of its problems has come to be acknowledged as security issues, which has resulted in many companies deciding not to deploy a cloud solution and instead retain their traditional system. This qualitative study will come to investigate the perspective of organizations regarding security within cloud computing. The aim is to outline the security aspects conferred by Swedish organizations as there already is existing information concerning security issues. The empirical study is based on the gathered information from conducted semi-structured interviews. This study resulted in the findings of seven security aspects outlined by organizations, with the main reason concerning the uncertainty and towards the services of cloud computing. These security aspects are essential as they are set by organizations that have the potentiality to become cloud users, but for certain reasons decide not to. From the outlined security aspects, a close relationship can be identified to the already known security problems. These problems have strengthened the meaning of the security aspects, and that they are based on real concerns that can be connected to real problems.

Dans ces travaux de recherche, nous proposons une méthodologie pour l’élaboration d’une architecture Cloud Manufacturing. Le CM est un paradigme émergeant dans lequel des ressources dynamiques virtualisées et extensibles sont fournies à un utilisateur comme services à travers internet. Notre architecture est utilisée comme une plateforme pour mettre en correspondance des utilisateurs et des fournisseurs de ressources manufacturières pouvant collaborer ensemble tout au long du cycle de vie du produit tout en réduisant les coûts et le temps de développement. Comme certains vendeurs peuvent décrire leurs services de différentes façons, les technologies du web telles que les ontologies sont des outils robustes pour mettre en correspondance les descriptions des vendeurs avec les requêtes des utilisateurs. Nous utilisons les ontologies pour élaborer le modèle de connaissance du domaine du Cloud Manufacturing. L’ontologie définit les étapes du cycle de vie du produit comme des services et prend en compte les caractéristiques du Cloud Computing (stockage, capacité de calcul, etc.). L’ontologie CM contribue à automatiser la découverte des services et est incluse dans la plateforme pour mettre en correspondance des utilisateurs et les fournisseurs. La méthodologie proposée (ASCI-Onto) est inspirée par le cadre méthodologique ASCI qui a déjà été utilisé pour l’étude de systèmes logistiques, hospitaliers et de production. L’objectif de cette nouvelle méthodologie est de développer facilement une librairie de composants pour un système CM. Un exemple d’application avec un modèle de simulation, basé sur le logiciel CloudSim, est présenté. L’objectif est d’aider les industriels à prendre leurs décisions pour concevoir un système CM. / In this research, we introduce a methodology to build a CM architecture. Cloud Manufacturing is an emerging paradigm in which dynamically scalable and virtualized resources are provided to the users as services over the Internet. Our architecture serves as a platform for mapping users and manufacturing resources' providers with the aim of enhancing collaboration within Product Lifecycle Management (PLM) by reducing costs and development time. Since some providers may use different descriptions of their services we believe that semantic web technologies like ontologies are robust tools for mapping providers' descriptions and users' requests in order to find the suited service. Then, we use ontology to build the knowledge model of Cloud Manufacturing domain. The ontology defines the steps of the pro- duct lifecycle as services and also takes in account the Cloud Computing features (storage, Computing capacity, etc.). The Cloud Manufacturing ontology contributes to intelligent and automated service discovery and is included in a platform for mapping users and providers. The proposed methodology ASCI-Onto is inspired by ASDI framework (analysis-specification- design-implementation) which has already been used in supply chain, healthcare and manu- facturing domains. The goal of the new methodology consists of designing easily a library of components for a Cloud Manufacturing system. Finally, an example of application of this methodology with a simulation model, based on the CloudSim software, is presented. The goal is to help industrials to make their decisions in order to design Cloud Manufacturing systems.