This study was undertaken to investigate whether there is a performance management system within the security industry, applicable specifically to Security Officers. To investigate which performance factors, apply to security officers and how security officers perceived performance management. The management of Security Officers’ performance is an aspect of management which has not garnered much interest compared to other operational and management areas – hence the paucity of research on the performance management of security officers. They make a major contribution to the labour market with 7 949 security companies listed on the Private Security Industry Regulatory Authority (PSIRA) website, and 2 973 companies (37%) based in Gauteng alone. However, despite the high number of companies, the industry has attracted the least attention in terms of performance. The overall research purpose of this study was to explore the management of security officers’ performance in a private security company operating in South Africa,focussing specifically on a company based in the Gauteng Province. The scope of the study was aimed at investigating security officers’ perception of performance management and to link performance to actual job performance and security officers’ perceived work performance. The researcher also investigated whether biographical factors had an influence on security officers’ performance. A quantitative research methodology was utilised to conduct the study. The main research instruments were primary data, comprising a self-developed questionnaire and secondary data, comprising company records. The respondents consisted of security officers whom had been subjected to the Dependability and Safety Instrument (DSI) during the period 2013 to 2015, in the region, who were still employed at the company at the time of the study. The findings of the study identified 11 performance management factors and indicated links between self-reported and actual work performance. Biographical characteristics did not seem to influence the work performance of the security officers. However, the results did indicate that employees with less tenure were more prone to disciplinary action by the company and those with higher levels of education were prone to fewer disciplinary actions and dismissals based on AWOL. The study identified the areas that play a significant role in the management of security officers’ performance. The identification of performance management factors in the security industry and security officers’ perceptions about performance management should enable HR officers to develop and implement a performance management system that will contribute to better service delivery to both internal and external clients in this industry. / Business Management / M. Com. (Business Management)

How to quantify security is a classic question in the security community that until today has had no plausible answer. Unfortunately, current security evaluation models are often either quantitative but too specific (i.e., applicability is limited), or comprehensive (i.e., system-level) but qualitative. The importance of quantifying security cannot be overstated, but doing so is difficult and complex, for many reason: the “physics” of the amount of security is ambiguous; the operational state is defined by two confronting parties; protecting and breaking systems is a cross-disciplinary mechanism; security is achieved by comparable security strength and breakable by the weakest link; and the human factor is unavoidable, among others. Thus, security engineers face great challenges in defending the principles of information security and privacy. This thesis addresses model-based system-level security quantification and argues that properly addressing the quantification problem of security first requires a paradigm shift in security modeling, addressing the problem at the abstraction level of what defines a computing system and failure model, before any system-level analysis can be established. Consequently, we present a candidate computing systems abstraction and failure model, then propose two failure-centric model-based quantification approaches, each including a bounding system model, performance measures, and evaluation techniques. The first approach addresses the problem considering the set of controls. To bound and build the logical network of a security system, we extend our original work on the Information Security Maturity Model (ISMM) with Reliability Block Diagrams (RBDs), state vectors, and structure functions from reliability engineering. We then present two different groups of evaluation methods. The first mainly addresses binary systems, by extending minimal path sets, minimal cut sets, and reliability analysis based on both random events and random variables. The second group addresses multi-state security systems with multiple performance measures, by extending Multi-state Systems (MSSs) representation and the Universal Generating Function (UGF) method. The second approach addresses the quantification problem when the two sets of a computing system, i.e., assets and controls, are considered. We adopt a graph-theoretic approach using Bayesian Networks (BNs) to build an asset-control graph as the candidate bounding system model, then demonstrate its application in a novel risk assessment method with various diagnosis and prediction inferences. This work, however, is multidisciplinary, involving foundations from many fields, including security engineering; maturity models; dependability theory, particularly reliability engineering; graph theory, particularly BNs; and probability and stochastic models.

How to quantify security is a classic question in the security community that until today has had no plausible answer. Unfortunately, current security evaluation models are often either quantitative but too specific (i.e., applicability is limited), or comprehensive (i.e., system-level) but qualitative. The importance of quantifying security cannot be overstated, but doing so is difficult and complex, for many reason: the “physics” of the amount of security is ambiguous; the operational state is defined by two confronting parties; protecting and breaking systems is a cross-disciplinary mechanism; security is achieved by comparable security strength and breakable by the weakest link; and the human factor is unavoidable, among others. Thus, security engineers face great challenges in defending the principles of information security and privacy. This thesis addresses model-based system-level security quantification and argues that properly addressing the quantification problem of security first requires a paradigm shift in security modeling, addressing the problem at the abstraction level of what defines a computing system and failure model, before any system-level analysis can be established. Consequently, we present a candidate computing systems abstraction and failure model, then propose two failure-centric model-based quantification approaches, each including a bounding system model, performance measures, and evaluation techniques. The first approach addresses the problem considering the set of controls. To bound and build the logical network of a security system, we extend our original work on the Information Security Maturity Model (ISMM) with Reliability Block Diagrams (RBDs), state vectors, and structure functions from reliability engineering. We then present two different groups of evaluation methods. The first mainly addresses binary systems, by extending minimal path sets, minimal cut sets, and reliability analysis based on both random events and random variables. The second group addresses multi-state security systems with multiple performance measures, by extending Multi-state Systems (MSSs) representation and the Universal Generating Function (UGF) method. The second approach addresses the quantification problem when the two sets of a computing system, i.e., assets and controls, are considered. We adopt a graph-theoretic approach using Bayesian Networks (BNs) to build an asset-control graph as the candidate bounding system model, then demonstrate its application in a novel risk assessment method with various diagnosis and prediction inferences. This work, however, is multidisciplinary, involving foundations from many fields, including security engineering; maturity models; dependability theory, particularly reliability engineering; graph theory, particularly BNs; and probability and stochastic models.

It is a fact that software has bugs. These bugs can lead to failures. Especially dependability and security failures are a great threat to software users. This thesis introduces four novel approaches that can be used to automatically harden software at the user's site. Automatic hardening removes bugs from already deployed software. All four approaches are automated, i.e., they require little support from the end-user. However, some support from the software developer is needed for two of these approaches. The presented approaches can be grouped into error toleration and bug removal. The two error toleration approaches are focused primarily on fast detection of security errors. When an error is detected it can be tolerated with well-known existing approaches. The other two approaches are bug removal approaches. They remove dependability bugs from already deployed software. We tested all approaches with existing benchmarks and applications, like the Apache web-server.

Military Strategy is defined as a plan at the military strategic level of war that consists of a set of military strategic ends, ways and means and the relationships between them. This definition leads to the following research questions: 1. How can the extent of the many-to-many relationships that exist between a military strategy, its ends, ways and means be quantified? 2. If the relationships between a military strategy, its ends, ways and means are quantified and if the effectiveness of the force design elements is known, how shall that enable the quantification of the state’s ability to execute its military strategy? 3. If the relationships between a military strategy, its ends, ways and means are quantified and if the effectiveness of the force design elements is known, how will it aid decision-making about the acquisition of the future force design? The first research question is answered by mapping a military strategy complete with its ends, ways and means to a ranked tree where the entities in the strategy corresponds with the vertices of different rank in the tree. The tree representation is used to define and determine the contribution of entities in a military strategy to entities at the next higher level. It is explained how analytical, heuristic and judgement methods can be employed to find the relative and real contribution values. Also, a military strategy for South Africa is developed to demonstrate the concept. The second research question is answered by developing measures of effectiveness taking the interdependence of entities at the terminal vertices of the ranked tree into account. Thereafter, the degree to which the force design would support the higher order entities inclusive of a military strategy could be calculated. The third research question is answered by developing a cost-benefit analysis method and a distance indicator from an optimal point to aid in deciding between supplier options for acquisition. Thereafter the knapsack problem is amended to allow for scheduling acquisition projects whilst optimising the force design's support of a military strategy. Finally, the model is validated and put into a contextual framework for use in the military. / Operations Management / D.Phil.

La complexité croissante du matériel et du logiciel dans le développement des applications pour les systèmes embarqués induit de nouveaux besoins et de nouvelles contraintes en termes de fonctionnalités, de capacité de stockage, de calcul et de consommation d'énergie. Cela entraîne des difficultés accrues pour les concepteurs alors que les contraintes commerciales liées aux développement et à la production de ces systèmes demeurent impondérables. Un autre défi qui s'ajoute à cette complexité est le développement des applications avec de fortes exigences de sécurité et de fiabilité (S&D) pour des systèmes embarqués contraints en ressources (RCES). De ce fait, nous recommandons d'aborder cette complexité via la réutilisation d'un ensemble d'artefacts de modélisation dédiés. Le "patron" constitue l'artefact de base pour représenter des solutions S&D, à spécifier par les experts de ces aspects et à réutiliser par les ingénieurs pour résoudre les problèmes de l'ingénierie système/logicielle du domaine confrontée à ces aspects. Dans le cadre de cette thèse, nous proposons une approche d'ingénierie à base de modèles pour la spécification, le packaging et la réutilisation de ces artefacts pour modéliser et analyser ces systèmes. Le fondement de notre approche est un ensemble de langages de modélisation et des règles de transformation couplés à un référentiel orienté modèles et de moteurs de recherche et d'instantiation. Ces langages de modélisation permettent de spécifier les patrons, les systèmes de patrons et un ensemble de modèles de propriétés et de ressources. Ces modèles permettent de gouverner l'utilisation des patrons, leur organisation et leur analyse pour d'éventuel réutilisation. Pour les transformations, nous avons conçu un ensemble de règles pour l'analyse de la satisfiabilité des architectures logicielles à base de patrons S&D pour des plateformes matérielles à base de modèles de ressources. Pour le développement du référentiel, nous proposons un processus de spécification et de génération basé sur les langages de modélisation décrits au préalable. Les moteurs permettent de retrouver pour ensuite instantier ces artefacts vers des environnements de développement spécifiques.Dans le cadre de l'assistance pour le développement des applications S&D pour les RCES, nous avons implémenté une suite d'outils, basés sur Eclipse EMF/QVTO, pour supporter la spécification de ces artefacts et l'analyse des applications S&D autour d'un référentiel. Afin de faciliter l'utilisation de l'approche proposée, nous préconisons un ensemble de méthodes pour favoriser l'utilisation de cette suite d'outils tout au long du processus de développement. En outre, nous avons abordé la construction par génération automatique de référentiels orientés modèles, basée sur Eclipse EMF/QVTO et la plateforme Eclispe CDO, accompagné d'un ensemble d'outils pour le peuplement, l'accès et la gestion de ce référentiel. Les problèmes étudiés dans ce travail ont été identifiés dans le contexte du projet européen FP7 TERESA. Les solutions proposées ont ainsi été démontrées et évaluées dans le cadre de ce projet à travers un cas d'étude d'une application de contrôle, exhibant des exigences de fiabilité et de sécurité, pour les systèmes ferroviaires. / Non-functional requirements such as Security and Dependability (S&D) become more and more important as well as more and more difficult to achieve, particularly in embedded systems development. Such systems come with a large number of common characteristics, including real-time and temperature constraints, security and dependability as well as efficiency requirements. In particular, the development of Resource Constrained Embedded Systems (RCES) has to address constraints regarding memory, computational processing power and/or energy consumption. In this work, we propose a modeling environment which associates model-driven paradigm and a model-based repository, to support the design and the packaging of S&D patterns, resource models and their property models. The approach is based on a set of modeling languages coupled with a model-repository, search and instantiation engines towards specific development environments. These modeling languages allow to specify patterns, resources and a set of property models. These property models will allow to govern the use of patterns and their analysis for reuse. In addition, we propose a specification and generation process of repositories. As part of the assistance for the development of S&D applications, we have implemented a suite of tool-chain based on the Eclipse platform to support the different activities around the repository, including the analysis activities. The proposed solutions were evaluated in the TERESA project through a case study from the railway domain.

Made available in DSpace on 2015-05-14T12:36:48Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4346482 bytes, checksum: 66ecee23f8ca75e6ea5bba135cfa9a42 (MD5) Previous issue date: 2014-01-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Background: With the growing popularity of cloud computing, an challenge seen in this discipline is the management of faults that may occur in such big infrastructures that, because of its size, has a greater chance of ocurring faults, errors and failures. A work that maps the solutions already created by researchers efficiently should help visualizing gaps over those research fields. Aims: This work aims to find research gaps in the cloud computing and fault management domains, aside from building a social network of researchers in the area. Method: We conducted a systematic mapping study to collect, filter and classify scientific works in this area. The 4535 scientific papers found on major search engines were filtered and the remaining 166 papers were classified according to a taxonomy described in this work. Results: We found that IaaS is most explored in the selected studies. The main dependability functions explored were Tolerance and Removal, and the attributes were Reliability and Availability. Most papers had been classified by research type as Solution Proposal. Conclusion: This work summarizes and classifies the research effort conducted on fault management in cloud computing, providing a good starting point for further research in this area. / Fundamentação: Com o grande crescimento da popularidade da computação em nuvens, observa-se que um desafio dessa área é gerenciar falhas que possam ocorrer nas grandes infra-estruturas computacionais construídas para dar suporte à computação como serviço. Por serem extensas, possuem maior ocorrência de faltas, falhas e erros. Um trabalho que mapeie as soluções já criadas por pesquisadores de maneira simples e eficiente pode ajudar a visualizar oportunidades e saturações nesta área de pesquisa. Objetivos: Este trabalho visa mapear de forma sistemática todo o esforço de pesquisa aplicado ao gerênciamento de faltas em computação em nuvem de forma a facilitar a identificação de áreas pouco exploradas e que pode eventualmente representar novas oportunidades de pesquisa. Metodologia: Para este trabalho utiliza-se a metodologia de pesquisa baseada em evidências, através do método de mapeamento sistemático, sendo a pesquisa construída em três etapas de seleção de estudos. Método: Conduzimos um mapeamento sistemático para coletar, filtrar e classificar trabalhos científicos na área. Foram inicialmente coletados 4535 artigos científicos nos grandes engenhos de busca que, após três etapas de filtragem, acabaram sendo reduzidos a 166 artigos. Estes artigos restantes foram classificados de acordo com a taxonomia definida neste trabalho. Resultados: Observa-se que IaaS é a área mais explorada nos estudos selecionados. As funções de gerência de falhas mais exploradas são Tolerância e Remoção, e os atributos são Confiabilidade e Disponibilidade. A maioria dos trabalhos foram classificados como tipo de pesquisa de Proposta de Solução. Conclusão: Este trabalho sumariza e classifica o esforço de pesquisa conduzido em Gerenciamento de Faltas em Computação em Nuvens, provendo um ponto de partida para pesquisas futuras nesta área.

Made available in DSpace on 2014-12-17T14:55:09Z (GMT). No. of bitstreams: 1 IvanovitchMDS_TESE_Capa_ate_pag78.pdf: 3947167 bytes, checksum: ce8af4212a09f9d5cf62d132879a91d3 (MD5) Previous issue date: 2013-01-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Ensuring the dependability requirements is essential for the industrial applications since faults may cause failures whose consequences result in economic losses, environmental damage or hurting people. Therefore, faced from the relevance of topic, this thesis proposes a methodology for the dependability evaluation of industrial wireless networks (WirelessHART, ISA100.11a, WIA-PA) on early design phase. However, the proposal can be easily adapted to maintenance and expansion stages of network. The proposal uses graph theory and fault tree formalism to create automatically an analytical model from a given wireless industrial network topology, where the dependability can be evaluated. The evaluation metrics supported are the reliability, availability, MTTF (mean time to failure), importance measures of devices, redundancy aspects and common cause failures. It must be emphasized that the proposal is independent of any tool to evaluate quantitatively the target metrics. However, due to validation issues it was used a tool widely accepted on academy for this purpose (SHARPE). In addition, an algorithm to generate the minimal cut sets, originally applied on graph theory, was adapted to fault tree formalism to guarantee the scalability of methodology in wireless industrial network environments (< 100 devices). Finally, the proposed methodology was validate from typical scenarios found in industrial environments, as star, line, cluster and mesh topologies. It was also evaluated scenarios with common cause failures and best practices to guide the design of an industrial wireless network. For guarantee scalability requirements, it was analyzed the performance of methodology in different scenarios where the results shown the applicability of proposal for networks typically found in industrial environments / Garantir os requisitos de dependabilidade ? fundamental para as aplica??es industriais, onde falhas podem conduzir a defeitos cujas consequ?ncias impactam em preju?zos econ?micos e principalmente danos ambientais e riscos aos operadores. Assim, diante da relev?ncia do tema, esta tese prop?em uma metodologia para an?lise da dependabilidade de redes industriais sem fio (WirelessHART, ISA100.11a, WIA-PA) ainda na fase de projeto. Entretanto, a proposta pode ser facilmente estendida para as fases de manuten??o e expans?o da rede. A proposta utiliza a teoria de grafos e o formalismo de ?rvores de Falhas para criar automaticamente um modelo anal?tico a partir de uma dada topologia de rede industrial sem fio, onde a dependabilidade possa ser avaliada. As m?tricas de avalia??o suportadas compreendem confiabilidade, disponibilidade e MTTF (tempo m?dio para falha) da rede, como tamb?m medidas de import?ncia dos dispositivos, aspectos de redund?ncia e defeitos em modo comum. Ressalta-se que a proposta independe de qualquer ferramenta para analisar quantitativamente as m?tricas visadas. Contudo, para prop?sito de valida??o da proposta utilizou-se uma ferramenta amplamente aceita na academia para esse fim (SHARPE). Adicionalmente, um algoritmo para gera??o dos cortes m?nimos originalmente aplicado na teoria de grafos foi adaptado para o formalismo das ?rvores de Falhas com o objetivo de garantir escalabilidade da metodologia ?s redes industriais sem fio (< 100 dispositivos). Finalmente, a metodologia proposta foi validada a partir de cen?rios t?picos encontrados em ambientes industriais, como topologias estrela, linha, cluster e mesh. Foram tamb?m avaliados cen?rios com defeitos em modo comum e um conjunto de pol?ticas a serem seguidas na cria??o de uma rede industrial sem fio. Para garantir aspectos de escalabilidade, uma an?lise de desempenho foi conduzida, onde pode-se observar a aplicabilidade da metodologia para as redes tipicamente encontradas em ambientes industriais

Dans une composition de services Web basée protocole, un ensemble de services composants se collaborent pour donner lieu à un service Composite. Chaque service est représenté par un automate à états finis (AEF). Au sein d’un AEF, chaque transition exprime l’exécution d’une opération qui fait avancer le service vers un état suivant. Une exécution du composite correspond à une séquence de transitions où chacune est déléguée à un des composants. Lors de l’exécution du composite, un ou plusieurs composants peuvent devenir indisponibles. Ceci peut produire une exécution incomplète du composite, et de ce fait un recouvrement est nécessaire. Le recouvrement consiste à transformer l’exécution incomplète en une exécution alternative ayant encore la capacité d’aller vers un état final. La transformation s'effectue en compensant certaines transitions et exécutant d’autres. Cette thèse présente une étude formelle du problème de recouvrement dans une composition de service Web basée protocole. Le problème de recouvrement consiste à trouver une meilleure exécution alternative parmi celles disponibles. Une meilleure alternative doit être atteignable à partir de l’exécution incomplète avec un nombre minimal de compensations visibles (vis-à-vis le client). Pour une exécution alternative donnée, nous prouvons que le problème de décision associé au calcul du nombre de transitions invisiblement compensées est NP-Complet. De ce fait, nous concluons que le problème de décision associé au recouvrement appartient à la classe ΣP2. / In a protocol-based Web service composition, a set of available component services collaborate together in order to provide a new composite service. Services export their protocols as finite state machines (FSMs). A transition in the FSM represents a task execution that makes the service moving to a next state. An execution of the composite corresponds to a sequence of transitions where each task is delegated to a component service. During composite run, one or more delegated components may become unavailable due to hard or soft problems on the Network. This unavailability may result in a failed execution of the composite. We provide in this thesis a formal study of the automatic recovery problem in the protocol-based Web service composition. Recovery consists in transforming the failed execution into a recovery execution. Such a transformation is performed by compensating some transitions and executing some others. The recovery execution is an alternative execution of the composite that still has the ability to reach a final state. The recovery problem consists then in finding the best recovery execution(s) among those available. The best recovery execution is attainable from the failed execution with a minimal number of visible compensations with respect to the client. For a given recovery execution, we prove that the decision problem associated with computing the number of invisibly-compensated transitions is NP-complete. Thus, we conclude that deciding of the best recovery execution is in ΣP2.

Abstract Radio communication is used in increasingly diversified device typologies. Telecommunications with a reduced detrimental impact on health and environment, and an improved cost-efficiency and working lifetime are expected by institutions, end-users, operators and manufacturers. Moreover, with more networks present or more articulated systems, dependability of the entirety is to be ensured. The related need of efficiency in various compartments – such as in the use energy or the radio spectrum – and of effectiveness in adapting to changing operating conditions can be achieved with cognitive features. This dissertation addresses network reconfiguration and dependability by cognitive measures from multiple perspectives – each covered by a respective part of this work – providing guidelines for cognitive networks design. A rationalising view on cognitive networks with related taxonomies and models includes a discussion on the dynamics and interactions in networks operating closely and simultaneously (here, concurrent networks). While cognitive domains are specified for cognitive functions, with a more generic scope control functions are assigned to topological domains. This allows a flexible exploitation of the system design by decoupling the specification of system functions from their mapping onto network devices that will host them. As interaction plays an important role in many topical scenarios, a model for networked engineered cognitive entities comprising four categories (observation, interworking, consolidation, operation) and two levels (a cognitive frontier and a metacognitive hub) is presented here. Its cognitive phases are considered with regard to the other architectural elements. Moving the focus down to the levers for exploitation of context awareness, are presented solutions for efficient use of resources and dependability in general, considering the network dynamics. For communication link and network adaptation, the effective capacity is captured by a compact-form expression also considering imperfections, while learning is exploited for reducing overhead, and collaboration for fairly maximising energy save. / Tiivistelmä Käyttäjät, operaattorit ja laitevalmistajat toivovat tulevilta tietoliikennejärjestelmiltä sekä aiempaa pienempiä haitallisia vaikutuksia terveyteen ja ympäristöön että parannettua kustannustehokkuutta ja toiminta-aikaa. Lisäksi olisi varmistettava useiden verkkojen ja niiden muodostamien monimutkaisten järjestelmien kokonaisuuden luotettava toiminta. Tarvittava tehokkuus energian ja radioresurssien käytössä, samoin kuin kyky sopeutua muuttuviin käyttötilanteisiin, voidaan saavuttaa kognitiivisilla radioteknikoilla. Tämä väitöskirja käsittelee kognitiivisten menetelmien tuomaa radioverkkojen mukauttamista ja luotettavuutta eri näkökulmista. Samalla esitetään kognitiivisten verkkojen suunnittelun periaatteita ja lähtökohtia. Väitöskirja sisältää katsauksen kognitiivisiin radioverkkoihin niihin liittyvine luokitteluineen ja malleineen, sekä tarkastelee samanaikaisesti ja läheisesti toimivien verkkojen (rinnakkaisten verkkojen) dynamiikkaa ja vuorovaikutuksia. Työssä määritetään kognitiiviset lohkot kognitiivisine toimintoineen, kun taas topologiset tasot hallintatoimintoineen määritetään yleisemmin. Tämä mahdollistaa järjestelmäsuunnittelun joustavan hyödyntämisen erottamalla järjestelmän toimintojen määrittelyn toteuttavista verkkolaitteista. Koska vuorovaikutus on merkittävä tekijä useissa sovellusskenaarioissa, verkottuneille keinotekoisille kognitiivisille yksiköille ehdotetaan tässä neljä luokkaa (havainnointi, yhteistoiminta, vakauttaminen, toiminta) sekä kaksi vyöhykettä (kognitiivinen raja-alue ja metakognitiivinen keskus) sisältävää mallia. Mallin kognitiiviset vaiheet käsitellään suhteessa muihin arkkitehtuurin elementteihin. Järjestelmän kontekstitietoisuuden hyväksikäyttöön liittyen esitetään ratkaisuja resurssien tehokkaaseen käyttöön ja yleisemmin luotettavuuteen ottaen huomioon verkkojen dynamiikkaa. Yhteyksien ja verkkojen mukauttamisesta esitetään analyyttinen ratkaisu saavutettavan tehollisen kapasiteetin määrittämiseksi, huomioiden mahdolliset epäideaalisuudet. Kognitiivista oppimista hyödynnetään hallintalikenteen vähentämiseksi ja yhteistyötä energiansäästön maksimoimiseksi verkon alueella tasapuolisesti.