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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Model upravljanja održavanjem objekata visokogradnje / Model for maintenance management in buildings

Dugonjić Dijana 24 April 2015 (has links)
<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>
12

Análise e síntese de sistemas multiplexados: uma abordagem de confiabilidade e manutenabilidade operacional. / Analysis and synthesis of multiplexed systems: an approach of reliability and operational maintainability.

Caetano, Ricardo Elias 10 April 2007 (has links)
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.
13

Análise e síntese de sistemas multiplexados: uma abordagem de confiabilidade e manutenabilidade operacional. / Analysis and synthesis of multiplexed systems: an approach of reliability and operational maintainability.

Ricardo Elias Caetano 10 April 2007 (has links)
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.
14

Propuesta de mejora de productividad en el área de electrólisis de una empresa metalúrgica usando herramientas Lean / Proposal for improving productivity in the electrolysis area of a metallurgical company using lean tools

Toledo López, Lenin Justino 10 September 2019 (has links)
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
15

Reliability-centred maintenance for electric power distribution systems

Bertling, Lina January 2002 (has links)
No description available.
16

Scheduled maintenance policy for minimum cost : a case study

Tabikh, Mohamad, Khattab, Ammar January 2011 (has links)
This report evaluate the maintenance policies that been applied within specific industrial company, Taken into considerations all corrective and preventive maintenance costs ,in addition to optimise best preventive maintenance schedule for minimum cost. Dynamate Intralog AB was the surveyed company that been encountered high maintenance cost compatible with less productivity, therefore obtaining maintenance schedule policy for minimum cost was the best solution for their problem, then by calculating their corrective and preventive maintenance cost the optimum time was acquired. Finally, the maintenance schedule approve that organized maintenance based on optimum time enhance the productivity and minimize the company maintenance cost.
17

Management System for Operations Mantenanace in Offshore Wind Turbine Plant

Ghanbari, Ahmad, Oyelakin, Muhydeen January 2012 (has links)
Management system for enhancing transfer of knowledge in wind power industry has not received sufficient research attention in recent times. In some cases, the wind power plant owner does not control the management system for operation and maintenance activities. Most of these wind power plants are under contract and rely upon the turbine vendor to perform most of the maintenance works and subsequently share their experience at the initial stage of operation. This research investigates the management system for the operations and maintenance activities of the offshore wind plant in Lillgrund. The research also explores the type of learning method that was adopted by the wind turbine vendor (Siemens) to transfer the operation and maintenance knowledge to the operator and owner (Vattenfall) within the speculated period. It was realized that in the next one year, the Vattenfall would be in full control of the operations and maintenance activities of the offshore wind power plant in Lillgrund. The co-management arrangement will give Siemens a good reputation and gainful experience in the wind power industry. The arrangement is achievable due to Siemens strategy to strive for constructive and long-standing relationships with their customer, based on trust, respect, and honesty. Vattenfall on the other hand, is aiming to be the partner of choice for their suppliers at the same time as best serving their internal customers. The provision for the training during the co-management period enables Siemens to strengthen their relationship with Vattenfall in this industry. In addition, Siemens also maintain close relationship with their customers and develop a large part of their portfolio, frequently on site. Vattenfall improves profitability and value creation, as a fundamental prerequisite for continued growth. The management systems of Vattenfall can be related to professional bureaucracy, this is due to the fact that it was organized to accommodate Siemens experts. Vattenfall benefits from the co-management activities of the operation and maintenance of the Lillgrund wind power plant for a specific period of time. The outcome of the research work has proven that there is an effective time-dependent proportionality for a gradual transfer of the technical knowledge of operation and maintenance from Siemens Wind AB to the Vattenfall personnel. The research started from the perspective of the maintenance method by Swedish standard for wind power, and the way things are being carried out in a more practical way in Lillgrund plant.
18

Based on Service Quality Management Perspective Assessing Productivity Maintenance and Preventive Maintenance on the Efficiency of Manufacturing Execution Systems

Lin, Chun-Huang 24 August 2010 (has links)
The industry of our country has turned to the Hi-Tech industry gradually, the competition among the same industry is fiercer and fiercer, different properties of industries move towards the road of the heterogeneous alliance gradually too. Under this rival environment, without doing out of the common being, the ability that will lose key competition soon withdraws , the management of making the respect is an indispensable ring too, because management is not good, even more advanced technology may be unable to consolidate enterprises in the position of the environment now. Service Quality Management (SQM) is a kind of management idea that can be suitable for various trades, the service pointed herein refers to various functions that all industries offer in general. This research will canvass the concept of Service Quality Management, use in our country the semiconductor assembly factory of Manufacturing Execution System (MES), embed Preventive Maintenance and Productivity Maintenance Systematic association, in order to reach the different property systems, carry on discussion and analysis. The systems of two kinds of different ways, build the system which forms different management styles by way of simulation, and use Arena simulation software to simulation and analysis under different situation, and canvass its own benefits. The results can be regarded as the manufacturing industry reference basis while construct a Manufacturing Execution System into or revised.
19

Development of equations to determine the increase in pavement condition due to treatment and the rate of decrease in condition after treatment for a local agency pavement network.

Deshmukh, Maithilee Mukund. 2009 May 1900 (has links)
Cost effective maintenance of pavement sections requires timely preventive maintenance and planned rehabilitation treatments. Knowledge of the increase in condition due to application of treatment and the loss of condition after treatment are essential when deciding the maintenance and rehabilitation treatments. Any error in formulating these values can cause significant changes in recommendations provided. Many researchers have developed pavement performance prediction models; however, less research has been done on the impact of treatment actions on the condition of a pavement section after treatments. The objective of the research is to develop equations, using deterministic empirical method, that predict the increase in pavement condition and rate of decrease in pavement condition after treatment actions with respect to pavement condition just before the treatment. The equations are developed for different treatments and different functional class, and surface type combination to quantify the impact of the treatment for the use in pavement management system. These equations can be used to quantify the effects of different treatments for the use in pavement management system. Numerical illustration is presented using the data from the Metropolitan Transportation Commission-Pavement Management System software developed by the Metropolitan Transportation Commission (MTC) located in Oakland, California. A relation is observed between increase in pavement condition and pavement condition just before treatment for different treatments and different functional class and surface type combination. Hence the equations to determine the trend in increase in pavement condition for different treatments and different functional class and surface type combination are developed. For rate of decrease in pavement condition, due to large variability in the data the loss of pavement condition per year could not be related to pavement condition just before treatment. Hence the equations to determine the trend in loss in pavement condition after treatment could not be developed. The developed equations can be efficiently used to predict increase in pavement condition due to application of the treatment and the loss of pavement condition after treatment.
20

Machine Scheduling With Preventive Maintenances

Batun, Sakine 01 June 2006 (has links) (PDF)
In manufacturing environments, machines are usually subject to down periods due to various reasons such as preventive maintenance activities, pre-accepted jobs and pre-known material shortages. Among these reasons, preventive maintenance, which is defined as the pre-planned maintenance activities to keep the machine in its operating state, has gained much more importance in recent years. In this thesis, we consider the single machine total flow time problem where the jobs are non-resumable and the machine is subject to preventive maintenance activities of known starting times and durations. We propose a number of optimality properties together with the upper and lower bounding procedures. Using these mechanisms, we build a branch and bound algorithm to find the optimal solution of the problem. Our extensive computational study on randomly generated test instances shows that our algorithm can solve large-sized problem instances with up to 80 jobs in reasonable times. We also study a two-alternative maintenance planning problem with minor and major maintenances. We give an optimizing algorithm to find the timing of the maintenances, when the job sequence is fixed.

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