The reliability of ocean systems is dependent on organizational factors. It has been shown that low probability / high consequence system failures are overwhelmingly induced by organizational factors. However, no methodology is yet widely accepted for the evaluation of this phenomenon or its accurate quantification. A qualitative complementary approach is proposed based on the CANL (Complex Adaptive Non-Linear) model. In the first part, the understanding of organizational processes that affect reliability is sought. The approach is applied to several case studies based on published information: the "Story of a Platform Audit" (where no failure occurred) and some offshore accidents. A methodology is proposed to complement regular safety audit procedures. The approach is shown useful also to improve post-mortem investigations. In the second part, quantitative probabilistic formulations are revised, based on the understanding obtained through the previous approach. Some of the limitations of these quantitative methods are pointed out. The Reliability State of an Organization is defined and a ranking for its evaluation is proposed. Preliminary guidelines are presented for the use of this approach as a framework to identify suitable quantitative methods for a given case. The use of a qualitative approach is demonstrated. A different insight into organizational factors is achieved based on a disciplined approach that relies on experience. Significant conclusions regarding quantitative methods, their limitations and appropriate use, are obtained. / Graduation date: 1999

This research investigates risks arising from the mechanism of green building assessment tools that may impact on the consistency of their outcomes and render them ineffective in reliably fulfilling their goals in the building industry. None of the past efforts at developing assessment tools have focused on the risk aspects of assessment tools. Moreover, slowly the building industry has started placing considerable reliance on them without completely understanding the consequences of potential risks. The origin of risks lies in the realization that assessing sustainability in buildings is complex and full of conflicting concepts and opinions, and that amidst all this, assessment tools are expected to deliver multiple performance objectives and goals. Given that the importance of assessing sustainability in buildings cannot be ignored, it becomes extremely important that assessment tools are understood well and are free from risks. To accomplish this, an array of potential risks are systematically brought together using a risk categorization method, which facilitated a basis to critically analyse the literature in the light of risks. This addressed the acknowledged gap in the literature on risks relating to assessment tools. Four categories are discussed under this categorization. These categories provide a basis for the quantitative investigation, which applies techniques of uncertainty analysis to quantify these risks. In the quantitative investigation, uncertainty in 40 input parameters is propagated through several alternative forms of the mechanism of assessment tools. The input parameters are selected using the assessment data of a case study (Arts Faculty building, University of Sunshine Coast). The design of alternative forms of the mechanism is based on the identified risk categories and is carried out using a vehicle assessment tool (Green Building Tool). The uncertainty propagation is carried out using a risk analysis tool (@Risk). Descriptive statistics is deployed to analyse the results of the uncertainty propagations. Analysis of the results has brought an understanding and insights into various aspects of the mechanism in the context of their predisposition to increase or decrease risks. To ensure that an assessment tool's specific goals are fulfilled, the mechanism needs to be designed carefully so that it is low-risk and appropriate to the intent. By providing in-depth insights into the mechanism, the methodology and outcomes of this research are important for the future development of green building assessment tools.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, Sept. 2004. / Thesis Advisor(s): Karen Burke, Craig Rasmussen. Includes bibliographical references (p. 131). Also available online.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Mavris, Dimitri N.; Committee Member: German, Brian J.; Committee Member: Osburg, Jan; Committee Member: Ruffin, Stephen M.; Committee Member: Schrage, Daniel P.. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M. P. A.)--Texas State University-San Marcos, 2006. / "Spring 2006." Includes bibliographical references (leaves 72-74).

M.Phil. / The use of information systems has increased dramatically after the emergence of internet. Individuals, companies and organizations are becoming increasingly dependent on IT systems. Before technology and computers became such an important part of society, it was difficult to manage and control large organizations. Today computers enable the effective and efficient management of large organizations, therefore allowing them to spread throughout the country and world. Businesses are following latest advances in this era to remain competitive in the changing global market place. They use computers, automated IT systems and networks to gather, store, retrieve, process, and analyze information as well as to trade and communicate. The rapid advances in computer technology are largely a result of the research, development and design efforts of computer engineers. There is a direct correlation between a nation's wealth and scientific and technological capacity. The most effective way of taking our country forward is to enthuse our youth for science and technology. As the world makes rapid, sometimes breathtaking strides in the diverse fields of science and technology, South Africa more than ever needs qualified individuals who will use their skills and entrepreneurial spirit to enable our country to complete internationally with the best. However, Information systems and networks and their worldwide increasing usage have been accompanied by new and increasing risks. Data and information stored on and transmitted over information technology systems and networks are subject to threats from various means of unauthorized access, such as misuse, misappropriation, alteration, malicious code transmissions, denial of service or destruction and require appropriate safeguards. This research report will aim to emphasize the importance of risk management and its three activities; risk assessment, risk mitigation and evaluation and assessment. It will focus on activities that deal with the solution of problems through logical thinking, information system management This report will also deal with a case study that gives us real life examples of risk management experiences of one local computer hardware and software supplier companies. Information has become valuable assets that need to be protected after moving to a digital era and E-commerce. Protecting information can also be as critical as protecting other resources like money and physical assets.

The quantification of information security risks is currently highly subjective. Values for information such as impact and probability, which are estimated during risk analysis, are mostly estimated by people or experts internal or external to the organization. Because the estimation of these values is done by people, all with different backgrounds and personalities, the values are exposed to subjectivity. The chance of any two people estimating the same value for risk analysis information is rare. There will always be a degree of uncertainty and imprecision in the values estimated. It is therefore during the data-gathering phase of risk analysis that the problem of subjectivity lies. To address the problem of subjectivity, techniques that mathematically deal with and present uncertainty and imprecision are used to estimate values for probability and impact. During this research a model for the objective estimation of probability was developed. The model uses mostly input values that are entirely objective, but also a small number of subjective input values. It is in these subjective input values that fuzzy logic and Monte Carlo simulation come into play. Fuzzy logic takes a qualitative subjective value and gives it an objective value, and Monte Carlo simulation complements fuzzy logic by giving a cumulative distribution function to the uncertain, imprecise input variable. In this way subjectivity is dealt with and the result of the model is a probability value that is estimated objectively. The same model that was used for the objective estimation of probability was used to estimate impact objectively. The end result of the research is the combination of the models to use the objective impact and probability values in a formula that calculates risk. The risk factors are then calculated objectively. A prototype was developed as proof that the process of objective information security risk quantification can be implemented in practice. / Prof. L. Labuschagne

M.Com. (Computer Auditing) / This dissertation aims to explore the entity characteristics associated with the implementation of the board-level stand-alone risk management committee (RMC) in South Africa. We developed a battery of econometric models based on triangulation of corporate governance theories which linked an entity’s decision to set up a separate risk management committee (RMC) in its board structures as a dependent variable and a host of entity-specific factors as independent variables. Data collected from audited annual reports of 181 JSE-listed non-financial entities was analysed using logistics regression estimation procedures. Our results show a strong positive relationship between the likelihood that an entity would establish a separate RMC, on the one hand, and board independence, board size, entity size, and industry type, on the other. Our study fails to find support for the hypothesis that an entity’s characteristics – such as the independence of the board chairman, the use of Big Four audit firms, financial reporting risks, and levels of financial leverage – do influence an entity’s decision to form a separate RMC. Our findings emphasize the role that information asymmetry between executive and non-executive directors, agency cost and potential damage to reputation capital of directors; diversity in background, expertise, and skills of directors; economies of scale in absorbing RMC costs; and industry-specific institutions and norms play in an entity’s decision to form a separate RMC. The implication of our findings is that policy-makers should consider the size and composition of boards and also take cognizance of entity size and industry-specific idiosyncrasies in setting recommended corporate governance practices.

This thesis addresses the challenges associated with thermal management systems (TMS) evaluation and selection in the conceptual design of hypersonic, air-breathing vehicles with sustained cruise. The proposed methodology identifies analysis tools and techniques which allow the proper investigation of the design space for various thermal management technologies. The design space exploration environment and alternative multi-objective decision making technique defined as Pareto-based Joint Probability Decision Making (PJPDM) is based on the approximation of 3-D Pareto frontiers and probabilistic technology effectiveness maps. These are generated through the evaluation of a Pareto Fitness function and Monte Carlo analysis. In contrast to Joint Probability Decision Making (JPDM), the proposed PJPDM technique does not require preemptive knowledge of weighting factors for competing objectives or goal constraints which can introduce bias into the final solution. Preemptive bias in a complex problem can degrade the overall capabilities of the final design. The implementation of PJPDM in this thesis eliminates the need for the numerical optimizer which is required with JPDM in order to improve upon a solution. In addition, a physics-based formulation is presented for the quantification of TMS safety effectiveness corresponding to debris impact/damage and how it can be applied towards risk mitigation. Lastly, a formulation loosely based on non-preemptive Goal Programming with equal weighted deviations is provided for the resolution of the inverse design space. This key step helps link vehicle capabilities to TMS technology subsystems in a top-down design approach. The methodology provides the designer more knowledge up front to help make proper engineering decisions and assumptions in the conceptual design phase regarding which technologies show greatest promise, and how to guide future technology research.

Ces travaux s'intéressent à l'estimation de la fiabilité des évacuateurs de crues vannés. Le comportement fiabilistes de ces systèmes hydrauliques dépend à la fois d'événements aléatoires discrets, mais aussi de l'évolution d'une variable déterministe continue : ce sont des systèmes dynamiques hybrides. Pour ces systèmes, l'événement redouté est réalisé lorsque le niveau de la retenue atteint un seuil de sûreté. La démarche de fiabilité dynamique proposée dans cette thèse vise à prendre en compte l’information temporelle de la modélisation à la synthèse d'indicateurs fiabilistes pour l'aide à la décision et développe deux contributions :1) L'élaboration d'une base de connaissances dédiée à la description des évacuateurs de crue en termes de fiabilité dynamique. Chaque classe de composants est décrite par un automate stochastique hybride dont les états sont les différentes phases de son fonctionnement. 2) Le suivi de la simulation de Monte Carlo et le traitement et l'analyse des "histoires" (séquence de tous les états activés et des dates d'activation) obtenues en simulation pour construire des indicateurs de fiabilité classique (probabilité d'occurrence de l'évènement redouté, identification des coupes équivalentes prépondérantes, ...). Des indicateurs de fiabilité dynamique basés sur la classification des histoires en fonction des dates de défaillance des composants concernés et sur l'estimation de l'importance dynamique sont aussi proposés / Hydraulic systems are hybrid dynamic systems whose evolution is a combination between discrete stochastic events on the one hand and continuous deterministic phenomena on the other hand. The undesired event is achieved when the dam level reaches a security threshold. In the frame of gated spillways dynamic reliability, the proposed methodology takes into account the temporal information during modeling and synthesis of reliability indicators for decision support.The first contribution of this work is the development of a knowledge base to describe a class of systems. Each component is described by a stochastic hybrid automaton whose states are the different working modes.The second contribution is Monte Carlo simulation monitoring and treatment results. A story is the sequence of all activated states and activation dates during the algorithm passage for a simulation. The analysis of results provides classical reliability indicators, such as the time evolution of the undesired event probability or the identification of predominant equivalent cuts. Our predictive approach is based on stories classification depending on components failure dates, then dynamic importance is assessed