A power system is normally composed of a large number of generators and transmission lines that are connected through switching stations and substations. The quality and availability of power supply to the customer is highly dependent on the performance of the station equipment. Research shows that station related outages can have considerable impact on the composite system reliability. The individual station components, the station configurations and the terminal connection topologies are important factors in bulk system reliability evaluation. The major components in a station are circuit breakers, bus bars and transformers and these elements are periodically removed from service in order to conduct preventive maintenance. The removal of equipment for maintenance creates a change in the station configuration and a more vulnerable system. The failure of a related major component during a station preventive maintenance outage can result in a system disturbance and customer load loss. The bulk of the existing infrastructure of most electric power systems has been installed over the last 30 to 50 years. Aging failures of system components are a growing issue in modern electric power systems. Station related preventive maintenance outages and aging failures are important factors that affect the system reliability. This thesis examines the reliability implications of station related outages, including maintenance outages and aging outages in basic station configurations using two practical test systems. Models and techniques are created to incorporate these outages in composite system reliability evaluation. The techniques presented and the quantitative analyses illustrated in this thesis provide valuable information for a wide range of system planning, design, reinforcement and maintenance applications, including design and modification of power stations and station maintenance planning.

A power system is normally composed of a large number of generators and transmission lines that are connected through switching stations and substations. The quality and availability of power supply to the customer is highly dependent on the performance of the station equipment. Research shows that station related outages can have considerable impact on the composite system reliability. The individual station components, the station configurations and the terminal connection topologies are important factors in bulk system reliability evaluation. The major components in a station are circuit breakers, bus bars and transformers and these elements are periodically removed from service in order to conduct preventive maintenance. The removal of equipment for maintenance creates a change in the station configuration and a more vulnerable system. The failure of a related major component during a station preventive maintenance outage can result in a system disturbance and customer load loss. The bulk of the existing infrastructure of most electric power systems has been installed over the last 30 to 50 years. Aging failures of system components are a growing issue in modern electric power systems. Station related preventive maintenance outages and aging failures are important factors that affect the system reliability. This thesis examines the reliability implications of station related outages, including maintenance outages and aging outages in basic station configurations using two practical test systems. Models and techniques are created to incorporate these outages in composite system reliability evaluation. The techniques presented and the quantitative analyses illustrated in this thesis provide valuable information for a wide range of system planning, design, reinforcement and maintenance applications, including design and modification of power stations and station maintenance planning.

Today's technological systems are expected to perform at very high standards throughout their operational phase. The cost associated with unavailability of these systems is very high and especially with the defense systems or medical equipment which can directly affect human lives. The maintenance system plays an important role in achieving higher performance targets. In order to manage maintenance activities in more informed and rational manner, it is very important to understand the inherently complex and dynamic structure of the system. Traditionally maintenance policies are derived from reliability characteristics of individual components or sub-systems. This research makes an attempt to understand the system from the forest level and suggest better maintenance policies for achieving higher availability and lower system degradation. The leverage is gained from System Dynamics framework's ability to model complex systems and capture various feedback loops. The simulation results reveal that with the limited preventive maintenance capacity and within the given assumptions of the model, there exists and optimal preventive maintenance interval which is not the minimum. The simulation results also reflect that frequent preventive maintenance is required at higher load factors. / Master of Science

abstract: Pavement preservation is the practice of selecting and applying maintenance activities in order to extend pavement life, enhance performance, and ensure cost effectiveness. Pavement preservation methods should be applied before pavements display significant amounts of environmental distress. The long-term effectiveness of different pavement preservation techniques can be measured in terms of life extension, relative benefit, and benefit-cost ratio. Optimal timing of pavement preservation means that the given maintenance treatment is applied so that it will extend the life of the roadway for the longest possible period with the minimum cost. This document examines the effectiveness of chip seal treatment in four climatic zones in the United States. The Long-Term Pavement Performance database was used to extract roughness and traffic data, as well as the maintenance and rehabilitation histories of treated and untreated sections. The sections were categorized into smooth, medium, and rough pavements, based upon initial condition as indicated by the International Roughness Index. Pavement performance of treated and untreated sections was collectively modeled using exponential regression analysis. Effectiveness was evaluated in terms of life extension, relative benefit, and benefit-cost ratio. The results of the study verified the assumption that treated sections performed better than untreated sections. The results also showed that the life extension, relative benefit, and benefit cost ratio are highest for sections whose initial condition is smooth at the time of chip seal treatment. These same measures of effectiveness are lowest for pavements whose condition is rough at the time of treatment. Chip seal treatment effectiveness showed no correlation to climatic conditions or to traffic levels. / Dissertation/Thesis / M.S. Civil Engineering 2012

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<p style="text-align: justify;">Vrednost objekata i njihova upotrebljivost opadaju vremenom usled neadekvatnog održavanja. Uobičajen model korektivnog održavanja postaje neprihvatljiv zbog toga što je ekonomski neodrživ. Reaktivno održavanje se zamenjuje proaktivnim održavanjem čijim se planiranjem nepredvidive intervencije svode na najmanju meru. To je moguće ostvariti uvođenjem savremene organizacije upravljanja održavanjem. Za kvalitetno održavanje neophodno je postojanje baze podataka koja omogućava planiranje i kontrolu aktivnosti na održavanju objekata.</p> / <p style="text-align: justify;">The value of buildings as well as their utilization declines over the time due to<br />inadequate maintenance. Usual method of corrective maintenance becomes<br />unacceptable due to its economic unsustainability. Reactive maintenance is<br />replaced by proactive maintenance the planning of which provides for<br />reduction of unpredictable interventions to the greatest possible extent. This<br />can be achieved by introducing modern organization of maintenance<br />management. With a view to establishing quality maintenance, it is<br />necessary to have the data base which enables planning and supervision of<br />building maintenance activities.</p>

O trabalho apresentado sob o título \"Análise e Síntese de Sistemas Multiplexados: Uma Abordagem de Confiabilidade e Manutenabilidade Operacional\" tem como objetivo propor um modelo prático para a manutenção, baseado na confiabilidade e manutenabilidade de componentes. Os dados desse trabalho foram obtidos através de relatórios gerenciais da Empresa de Telecomunicações de São Paulo S/A, no período de janeiro/05 a junho/06, para as topologias de rede em anel e ponto a ponto da cidade de São Paulo, municípios da Grande São Paulo, Vale do Paraíba e Litoral do Estado de São Paulo. Com esses dados, foi utilizado o algoritmo de Weibull, cujo modelo probabilístico permite modelar vários tipos de resultados experimentais e operacionais. Dessa forma, foram determinados a confiabilidade operacional, o Tempo Médio de Bom Funcionamento (MTTF), a manutenabilidade, o Tempo Médio de Reparo (MTTR) e a disponibilidade para os componentes da rede externa óptica e dos equipamentos de rede da topologia de rede em anel e ponto a ponto. Observou-se que o equipamento de rede de Multiplexação Densa por Divisão do Comprimento de Onda (DWDM) apresenta uma confiabilidade operacional maior que a dos Equipamentos de Rede Tradicionais (ERT), independente da topologia de rede utilizada. Comparando-se o custo de implantação de uma rede óptica com DWDM e ERT, a uma taxa de transmissão de 2,5 Gbps, pode ser verificado que o custo é aproximadamente sete vezes menor quando se utiliza a rede óptica com DWDM. Por fim, foi feita uma comparação entre o custo total e médio da manutenção corretiva e preventiva para as topologias analisadas. Assim, pode ser concluído que a tecnologia DWDM é a opção mais vantajosa em termos de confiabilidade e manutenabilidade em relação ao ERT. / The work presented under the heading \"Analysis and Synthesis of Multiplexed Systems: An Approach of Reliability and Operational Maintainability\" has as objective to consider a practical model for the maintenance, based on the reliability and maintainability of components. The data of this work had been gotten through management reports of the Company of Telecommunications of São Paulo S/A, in the period of january/05 to june/06, for the in ring and point to point network topologies of the city of São Paulo, cities of the Great São Paulo, Valley of Paraíba and the coast of the State of São Paulo. With these data, it was used the algorithm of Weibull, whose probabilistic model allows to model many types of experimentals and operationals results. Of this form, were determined the operational reliability, the Mean Time To Failure (MTTF), the maintainability, the Mean Time To Repair (MTTR) and the availability for the components of the fiber optic external network and the network equipments of the in ring and point-to-point network topology. It was observed that the network equipment of Dense Wavelength Division Multiplexing (DWDM) presents a greater operational reliability that the Traditionals Network Equipments (ERT), independent of the network topology used. Comparing itself the cost of implantation of an fiber optic network with DWDM and ERT, to a rate of transmission of 2,5 Gbps, it could be verified that the cost is approximately seven times lesser when it is used the fiber optic network with DWDM. Finally, a comparison between the total and average cost of the corrective and preventive maintenance for the analyzed topologies was made. So, it can be concluded that the technology DWDM is the option most advantageous in terms of reliability and maintainability in relation to the ERT.

O trabalho apresentado sob o título \"Análise e Síntese de Sistemas Multiplexados: Uma Abordagem de Confiabilidade e Manutenabilidade Operacional\" tem como objetivo propor um modelo prático para a manutenção, baseado na confiabilidade e manutenabilidade de componentes. Os dados desse trabalho foram obtidos através de relatórios gerenciais da Empresa de Telecomunicações de São Paulo S/A, no período de janeiro/05 a junho/06, para as topologias de rede em anel e ponto a ponto da cidade de São Paulo, municípios da Grande São Paulo, Vale do Paraíba e Litoral do Estado de São Paulo. Com esses dados, foi utilizado o algoritmo de Weibull, cujo modelo probabilístico permite modelar vários tipos de resultados experimentais e operacionais. Dessa forma, foram determinados a confiabilidade operacional, o Tempo Médio de Bom Funcionamento (MTTF), a manutenabilidade, o Tempo Médio de Reparo (MTTR) e a disponibilidade para os componentes da rede externa óptica e dos equipamentos de rede da topologia de rede em anel e ponto a ponto. Observou-se que o equipamento de rede de Multiplexação Densa por Divisão do Comprimento de Onda (DWDM) apresenta uma confiabilidade operacional maior que a dos Equipamentos de Rede Tradicionais (ERT), independente da topologia de rede utilizada. Comparando-se o custo de implantação de uma rede óptica com DWDM e ERT, a uma taxa de transmissão de 2,5 Gbps, pode ser verificado que o custo é aproximadamente sete vezes menor quando se utiliza a rede óptica com DWDM. Por fim, foi feita uma comparação entre o custo total e médio da manutenção corretiva e preventiva para as topologias analisadas. Assim, pode ser concluído que a tecnologia DWDM é a opção mais vantajosa em termos de confiabilidade e manutenabilidade em relação ao ERT. / The work presented under the heading \"Analysis and Synthesis of Multiplexed Systems: An Approach of Reliability and Operational Maintainability\" has as objective to consider a practical model for the maintenance, based on the reliability and maintainability of components. The data of this work had been gotten through management reports of the Company of Telecommunications of São Paulo S/A, in the period of january/05 to june/06, for the in ring and point to point network topologies of the city of São Paulo, cities of the Great São Paulo, Valley of Paraíba and the coast of the State of São Paulo. With these data, it was used the algorithm of Weibull, whose probabilistic model allows to model many types of experimentals and operationals results. Of this form, were determined the operational reliability, the Mean Time To Failure (MTTF), the maintainability, the Mean Time To Repair (MTTR) and the availability for the components of the fiber optic external network and the network equipments of the in ring and point-to-point network topology. It was observed that the network equipment of Dense Wavelength Division Multiplexing (DWDM) presents a greater operational reliability that the Traditionals Network Equipments (ERT), independent of the network topology used. Comparing itself the cost of implantation of an fiber optic network with DWDM and ERT, to a rate of transmission of 2,5 Gbps, it could be verified that the cost is approximately seven times lesser when it is used the fiber optic network with DWDM. Finally, a comparison between the total and average cost of the corrective and preventive maintenance for the analyzed topologies was made. So, it can be concluded that the technology DWDM is the option most advantageous in terms of reliability and maintainability in relation to the ERT.

El presente trabajo aborda la problemática de una empresa del sector minero, específicamente se trata de una refinería de Zinc ubicada en el departamento de Lima, Perú. El campo de acción se centra en la planta de electrólisis, la cual tiene el problema de disminución de productividad (de 8.38 a 8.22 TN Zn/1000$en recursos) causadas por el consumo en exceso de energía eléctrica y aumento de mano de obra, generando resultados por debajo de los estándares internos del área y sobrecostos en recursos empleados para llegar a las metas productivas. Se utilizaron herramientas Lean para desarrollar propuestas de solución de la problemática, como el uso del SMED y Andon para lograr menores tiempos de preparación en actividades de eliminación de cortocircuitos (52%), Uso del Diagrama de Actividades Múltiples (30% de aumento de producción), Mantenimiento Preventivo para optimizar la frecuencia del mantenimiento y limpieza (reducción del 80% del costo de mano de obra extra) y la implementación de un programa de 5S para mejorar el orden y limpieza del área (aumento del 54% del índice de radar en 5S). A su vez se implementaron indicadores para monitorear el desarrollo de estas mejoras. Con la aplicación de estas herramientas se obtiene un ahorro de $378,522.00 en recursos, logrando aumentar el índice de productividad hasta su estándar interno (8.3). Estos resultados nos demuestran la utilidad de las herramientas Lean para la mejora de productividad en cualquier área que se puedan replicar, sirviendo como base para lograr la mejora contínua en las organizaciones. / The present paper addresses the problems of a mining company, specifically a Zinc refinery located in the department of Lima, Peru. The field of action focuses on the electrolysis plant, which has the problem of decreasing productivity (from 8.38 to 8.22 TN Zn / 1000 $ in resources) caused by the excessive consumption of electrical energy and increase of labor, generating results below the internal standards of the area and costs in resources used to reach the productive goals. Lean tools were used to develop proposals for solving the problem, such as the use of SMED and Andon to obtain shorter readiness times for short circuits (52%), Multiple Activity Diagram (30% increase in Production), Preventive Maintenance to optimize the frequency of maintenance and cleaning (reduction of 80% of the cost of extra labor) and implementation of a 5S program to improve the order and cleanliness of the area (54% increase in radar index in 5S). At the same time, indicators were implemented to monitor the development of these improvements. With the application of these tools you get a saving of $378,522.00 in resources, increasing the productivity index to its internal standard (8.3). These results demonstrate the usefulness of Lean tools for improving productivity in any area that can be replicated, serving as a basis for continuous improvement in organizations. / Trabajo de Suficiencia Profesional

No description available.