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Usinas hidrelétricas cotistas: aspectos técnicos e regulatórios sobre a qualidade do serviço prestado. / Regulated hydropower plants: technical and regulatory aspects about the quality of service.Gustavo Caravaggi Tenaglia 19 May 2017 (has links)
Esta Dissertação traz uma discussão sobre a necessidade de haver políticas de incentivo à existência de almoxarifado de operação em usinas hidrelétricas que renovaram suas concessões através da Lei 12.783/13 passando a pertencer ao regime de cotas de garantia física, e seus efeitos imediatos para a disponibilidade do sistema gerador e para a segurança de operação do sistema elétrico brasileiro, estabelecendo conexões do ambiente regulatório/econômico com o mundo físico/real. Com base nas teorias de confiabilidade, métodos de gestão de ativos e políticas de operação e manutenção, analisa-se a situação real do parque gerador hidrelétrico com mais de 30 anos de operação, e as consequências do aumento das taxas de falhas e redução de vida útil, explanando a necessidade de se promover uma forma de incentivo que corrija as assimetrias regulatórias estabelecidas, envolvendo as penalidades e os benefícios percebidos tanto pelo lado do agente regulado, quanto pelo lado do consumidor final. No texto deste trabalho, verifica-se uma discrepância entre os custos de O&M reais e regulatórios, induzindo duas análises possíveis: Para o caso em que as remunerações são superiores aos custos reais, a penalização proposta pelo regulador não é suficiente para induzir investimentos em almoxarifados, dado que o retorno não condiz com o custo de oportunidade do capital empregado. Já para o caso em que as remunerações são inferiores aos custos reais, as penalidades podem impor um desequilíbrio econômico-financeiro da gestão dos ativos, anulando os incentivos para manutenção da disponibilidade através da imobilização de ativos sobressalentes. Estes casos demonstram, de forma simples, a existência de uma falha no sinal dado pelo regulador para a manutenção da qualidade do serviço, medido através dos índices de disponibilidade. Ressalta-se que a degradação dos ativos pertencentes às usinas cotistas não só é prejudicial para a busca pela modicidade tarifária, mas também poderá ser crítica para a operação do sistema em um período em que as hidrelétricas existentes terão um papel fundamental o gerenciamento de carga com a entrada de fontes intermitentes no sistema elétrico brasileiro. Para isso, o trabalho está estruturado em sete capítulos: (1) introdução; (2) o modelo regulatório vigente; (3) usinas hidrelétricas e seus sistemas; (4) confiabilidade e taxa de falha; (5) estudo de caso 1 - qualidade do serviço prestado; (6) estudo de caso 2 - avaliação dos impactos sistêmicos e (7) considerações finais. / This Dissertation brings a discussion about the need of creating politics to incentive the existence of operational warehouses in Regulated Hydropower Plants, regarding the immediate effects in the availability and reliability of the Brazilian Electrical System - linking the regulatory environment to the physical world. Based in reliability theories, asset management theories and operational & maintenance polices, the work analyses the real performance of those he Regulated Hydropower Plants that are in operation for more than 30 years of operation, looking at the consequences of the growing of failure rates by going toward the end of the forecasted life-time of the main systems and equipment. By that, it aims to explain the need of promoting incentives that corrects the regulatory asymmetry involving the penalties and bonuses perceived by the regulated agent and the final consumer. Through this work, a discrepancy between the real and the regulatory O&M costs is noted, what leads to two different analysis: On the one hand, for those agents with regulated revenue greater than the real O&M costs, there is no incentive to spent their capital in spare parts due to the opportunity cost of that capital. On the other hand, the for those agent with regulated revenue lower than the real O&M costs, the penalties can easily impose an economic-financial imbalance, also nulling the incentives to immobilize assets in spare parts. Those two examples demonstrate in a simple way the failure in the sign given by the regulator to guarantee the quality of service of those Power Plants. It is divided into seven chapters: (1) introduction; (2) the current regulatory model; (3) hydropower plant and its systems; (4) reliability and failure rate; (5) study case 1 - quality of service; (6) study case 2 - evaluation of systemic impacts and (7) final considerations.
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Two-Echelon Supply Chain Design for Spare Parts with Time ConstraintsRiaz, Muhammad Waqas January 2013 (has links)
We consider a single-part, two-echelon supply chain problem for spare parts. The network consists of a single manufacturing plant, a set of service centers (SCs) and a set of customers. Both echelons keep spare parts using the base-stock replenishment policy. The plant behaves as an M/M/1 queueing system and has limited production and storage capacity. Demand faced by each SC follows an independent Poisson process. The problem is to determine optimal location-allocation and optimal base-stock levels at both echelons while satisfying the target service levels and customer preferences of SCs. We develop a mixed integer non-linear programming model and use cutting-plane method to optimize the inventory-location decisions. We present an exact solution procedure for the inventory stocking problem and demonstrate the limitations of using traditional inventory models like METRIC-like and Approximate in case of high utilization rates. We show the effectiveness of our proposed cutting-plane algorithm and provide important managerial insights for spare parts management.
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Incentive, Subsidy, Penalty Mechanisms And Pooled, Unpooled Allocation Of Production Capacity In Service Parts Management SystemsAtak, Erman 01 July 2011 (has links) (PDF)
In this thesis, two systems are analyzed in order to gain insight to the following
issues: (i) Effect of incentive, subsidy and penalty designs on decentralized system,
(ii) effect of using production facility as pooled capacity (pooled system) and
dedicated capacity (unpooled system) on capacity utilization and system profit.
Regarding the first issue, three models are defined / decentralized model, centralized
model and decentralized model with incentive, subsidy, penalty designs. In all
models, there are two dealers and one item is under consideration and lateral
transshipments are allowed. Dealers operate with four inventory level decision
(strategies) that consists of base stock level, rationing level, transshipment request
level and customer rejection level. Under the decentralized system, a dealer sets its
operating strategy according to the strategy of the other dealer and maximizes its
own infinite horizon discounted expected profit. In the centralized system, a central
authority (say manufacturer) exists, which considers the system-wide infinite
horizon discounted expected profit, and makes all decisions. Under decentralized
system with incentive, subsidy, penalty designs, manufacturer tries different designs
on decentralized system namely revenue sharing, holding cost subsidy, request
rejection penalty, transportation cost subsidy and commission subsidy in order to
v
align decentralized system with centralized system. According to the results
obtained, this alignment works best with nearly 40% revenue sharing percentage,
low rejection penalty, high transportation cost subsidy under low transportation cost
and commission subsidy under very low or very high commissions. Holding cost
subsidy, on the other hand, is not a good strategy since it declines decentralized
system profit. Considering the second issue, two systems are examined / pooled
system and unpooled system. Both systems are centrally managed. In the pooled
system, all capacity is dynamically allocated to either dealer considering
maximization of system profit. In the unpooled system, capacity is shared among
dealers and dealers are always allocated same percentage of the capacity. Infinite
horizon average expected profit is maximized in both systems. The dealer having
lower holding cost is allocated higher capacity in both pooled and unpooled system / however, exceptions exist in the unpooled system under low arrival rate. Highrevenue
dealer is always allocated higher capacity in both pooled and unpooled
system. Arrival rate affects both systems such that total capacity utilization increases
with increasing arrival rate. From the profit point of view, pooled system has great
advantage under low demand rate in general.
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Sensor-based prognostics and structured maintenance policies for components with complex degradationElwany, Alaa H. 23 September 2009 (has links)
We propose a mathematical framework that integrates low-level sensory signals from monitoring engineering systems and their components with high-level decision models for maintenance optimization. Our objective is to derive optimal adaptive maintenance strategies that capitalize on condition monitoring information to update maintenance actions based upon the current state of health of the system. We refer to this sensor-based decision methodology as "sense-and-respond logistics".
As a first step, we develop and extend degradation models to compute and periodically update the remaining life distribution of fielded components using in situ degradation signals. Next, we integrate these sensory updated remaining life distributions with maintenance decision models to; (1) determine, in real-time, the optimal time to replace a component such that the lost opportunity costs due to early replacements are minimized and system utilization is increased, and (2) sequentially determine the optimal time to order a spare part such that inventory holding costs are minimized while preventing stock outs.
Lastly, we integrate the proposed degradation model with Markov process models to derive structured replacement and spare parts ordering policies. In particular, we show that the optimal maintenance policy for our problem setting is a monotonically non-decreasing control limit type policy. We validate our methodology using real-world data from monitoring a piece of rotating machinery using vibration accelerometers. We also demonstrate that the proposed sense-and-respond decision methodology results in better decisions and reduced costs compared to other traditional approaches.
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Two-Echelon Supply Chain Design for Spare Parts with Time ConstraintsRiaz, Muhammad Waqas January 2013 (has links)
We consider a single-part, two-echelon supply chain problem for spare parts. The network consists of a single manufacturing plant, a set of service centers (SCs) and a set of customers. Both echelons keep spare parts using the base-stock replenishment policy. The plant behaves as an M/M/1 queueing system and has limited production and storage capacity. Demand faced by each SC follows an independent Poisson process. The problem is to determine optimal location-allocation and optimal base-stock levels at both echelons while satisfying the target service levels and customer preferences of SCs. We develop a mixed integer non-linear programming model and use cutting-plane method to optimize the inventory-location decisions. We present an exact solution procedure for the inventory stocking problem and demonstrate the limitations of using traditional inventory models like METRIC-like and Approximate in case of high utilization rates. We show the effectiveness of our proposed cutting-plane algorithm and provide important managerial insights for spare parts management.
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L'île aux tourtes (1703-1727) et les perles de traite dans l'archipel montréalaisMurray, Annie-Claude January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
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A structured approach for the reduction of mean time to repair of blast furnace D, ArcelorMittal, South Africa, Vanderbijlpark / Madonsela A.T.Madonsela, Alex Thulani January 2011 (has links)
Organizations are expected by their shareholders to continually deliver above
industry returns on capital invested and to remain competitive in the industry of
choice through productivity, safety and quality. The maintenance function is a key
area in which competitiveness through efficiencies and world–class performance can
be attained by focusing on the prevention and reduction of long and costly
equipment repair times.
The question is: how can the mean time to repair of equipment already installed in
the plant be reduced?
To answer the above question correctly and comprehensively, the research explored
mixed methods in finding answers. Quantitative methodology using a survey was
used for data collection. Observations and interviews were held with maintenance
personnel to uncover information that couldn’t have been obtained by means of a
survey.
The survey was limited to equipment performance measures, human factors,
environmental factors, planning, spare parts, maintainability, procedures and
training. To test consistency and accuracy of representation of the total population
under study, a reliability test was done by using Cronbach’s alpha coefficient. To
determine whether there are any differences between groups, an ANOVA test was
used. Cohen’s d–value was used to determine practically significant differences
between one set of data with another and correlation analysis was used to determine
the relationships between the variables.
The approach designed and delivered by this research flowed from the existing body
of knowledge, case studies and survey findings. The approach adopts some of the
elements of the failure mode and effects analysis (FMEA) procedure and differs from
other work that has been done by others by taking into account the competency and
experience of maintenance personnel and assigning to them factors which are used
to compute anew MTTR of the equipment. The cost of implementing the
recommended corrective actions for realising the new MTTR is determined and
evaluated against an improved equipment availability that will be achieved as a
result of the recommended corrective actions assuming that the failure rate of the
equipment remains constant. This evaluation step imbedded within the approach is
valuable for the maintenance function and management for decision making in
ensuring that resources at the organization’s disposal are used productively.
Validation and test results of the approach showed that the MTTR of equipment
installed in the plant can be reduced. The results also indicated that through the use
of the designed approach a regular pattern of repair or replacement times can be
followed well in advance and that it is practical, user friendly and it also delivers on
its objective of offering a structure for analysis and decision making aimed at
reducing the MTTR.
Included with this dissertation is feedback information that can be included in a
maintenance job card feedback section to capture information about factors that can
be improved to lower the MTTR as part of a continuous improvement process.
Included also is a spare part development and management procedure that can be
used by the maintenance function.
Recommendations on training of maintenance personnel on the maintainability of
equipment, the FMEA procedure and maintenance procedures are highlighted.
Information that flowed from this approach will be valuable for continuous plant
performance improvement and during the design, installation and operation stages of a blast furnace. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.
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A structured approach for the reduction of mean time to repair of blast furnace D, ArcelorMittal, South Africa, Vanderbijlpark / Madonsela A.T.Madonsela, Alex Thulani January 2011 (has links)
Organizations are expected by their shareholders to continually deliver above
industry returns on capital invested and to remain competitive in the industry of
choice through productivity, safety and quality. The maintenance function is a key
area in which competitiveness through efficiencies and world–class performance can
be attained by focusing on the prevention and reduction of long and costly
equipment repair times.
The question is: how can the mean time to repair of equipment already installed in
the plant be reduced?
To answer the above question correctly and comprehensively, the research explored
mixed methods in finding answers. Quantitative methodology using a survey was
used for data collection. Observations and interviews were held with maintenance
personnel to uncover information that couldn’t have been obtained by means of a
survey.
The survey was limited to equipment performance measures, human factors,
environmental factors, planning, spare parts, maintainability, procedures and
training. To test consistency and accuracy of representation of the total population
under study, a reliability test was done by using Cronbach’s alpha coefficient. To
determine whether there are any differences between groups, an ANOVA test was
used. Cohen’s d–value was used to determine practically significant differences
between one set of data with another and correlation analysis was used to determine
the relationships between the variables.
The approach designed and delivered by this research flowed from the existing body
of knowledge, case studies and survey findings. The approach adopts some of the
elements of the failure mode and effects analysis (FMEA) procedure and differs from
other work that has been done by others by taking into account the competency and
experience of maintenance personnel and assigning to them factors which are used
to compute anew MTTR of the equipment. The cost of implementing the
recommended corrective actions for realising the new MTTR is determined and
evaluated against an improved equipment availability that will be achieved as a
result of the recommended corrective actions assuming that the failure rate of the
equipment remains constant. This evaluation step imbedded within the approach is
valuable for the maintenance function and management for decision making in
ensuring that resources at the organization’s disposal are used productively.
Validation and test results of the approach showed that the MTTR of equipment
installed in the plant can be reduced. The results also indicated that through the use
of the designed approach a regular pattern of repair or replacement times can be
followed well in advance and that it is practical, user friendly and it also delivers on
its objective of offering a structure for analysis and decision making aimed at
reducing the MTTR.
Included with this dissertation is feedback information that can be included in a
maintenance job card feedback section to capture information about factors that can
be improved to lower the MTTR as part of a continuous improvement process.
Included also is a spare part development and management procedure that can be
used by the maintenance function.
Recommendations on training of maintenance personnel on the maintainability of
equipment, the FMEA procedure and maintenance procedures are highlighted.
Information that flowed from this approach will be valuable for continuous plant
performance improvement and during the design, installation and operation stages of a blast furnace. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.
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[en] APPLICATION OF RFID TECHNOLOGY IN THE SPARE PARTS SUPPLY CHAIN: A CASE STUDY ON BRAZILIAN NAVY SHIPS / [pt] APLICAÇÃO DA TECNOLOGIA RFID NA CADEIA DE SUPRIMENTO DE SOBRESSALENTES: UM ESTUDO DE CASO EM NAVIOS DA MARINHA DO BRASILROGERIO FERRAZ QUEIROZ MIRANDA 14 February 2017 (has links)
[pt] Atualmente, muitas organizações visam satisfazer as necessidades de clientes eliminando custos. Novas soluções inovadoras são adotadas para incrementar a eficiência da Logística, e em paralelo, reduzir custos operacionais com a utilização de Tecnologia da Informação (TI). A RFID (identificação por radiofrequência) é a TI que proporciona o incremento da integração, da eficiência e da eficácia em toda a cadeia analisada. Embora existam desafios afiançados para a implementação da tecnologia em materiais metálicos, há aplicações desenvolvidas neste nicho, incluindo pesquisas subsidiadas pela Marinha Americana. Benefícios e vantagens da RFID são expostos: incremento da precisão do inventário, redução do custo da mão de obra, mitigação de erros de registro, incremento dos níveis de serviço, aumento da integração e monitoramento de processos logísticos à jusante da cadeia. Neste contexto, este trabalho tem por objetivos analisar a viabilidade de implantação da tecnologia RFID nas Fragatas Classe Niterói - FCN, conservada a compatibilidade com os sistemas correntes, discorrendo as oportunidades contemporâneas, vantagens e benefícios da tecnologia orientada ao incremento da eficiência na cadeia de suprimentos de sobressalentes das FCN; evidenciar o ganho em custo de mão de obra nas operações de armazenagem e o incremento da precisão de inventário; e avaliar os requisitos técnicos e econômicos para a adoção da RFID nas FCN. Conclui-se que o modelo futuro com a RFID é viável e gera Retorno sobre Investimento - ROI de 2,24 utilizando apenas como benefício à redução do custo de mão de obra. Outros benefícios com base em benchmarking são evidenciados. / [en] Currently, many organizations seek to satisfy the needs of customers by eliminating costs. New innovative solutions are adopted to improve the efficiency of Logistics, and in parallel, reduce operational costs with the adoption of Information Technology (IT). RFID (radio frequency identification) is the IT that provides the improvement of integration, efficiency and effectiveness throughout the chain analyzed. Although there are challenges bailed by the technology implementation in metallic materials, there are applications developed on this niche, including researches subsidized by the U.S. Navy. Benefits and advantages of RFID are exposed: improvement of the inventory accuracy, reduction of the cost of labor, mitigation of registry errors, increase service levels, increase of the integration and of logistics processes monitoring towards the downstream chain. In this context, this paper aims to analyze the feasibility of RFID deployment technology in the Niterói Class Frigates - FCN, preserving the compatibility with the current systems, discussing contemporary opportunities, advantages and benefits of technology oriented to increase the efficiency of the FCN spare parts supply chain; show the gain in the cost of labors in warehouse operations and the improvement of the inventory accuracy; and evaluate the technical and economical requirements for the adoption of RFID in the FCN. We conclude that the future model with RFID is feasible and generate Return on Investment (ROI) of 2.24 using only as benefit the decreasing labor cost. Other benefits based on benchmarking are highlighted.
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Renovace nákladných náhradních dílu za využití speciálních strojírenských technologií. / Renovation of expensive spare parts using of special engineering technologies.DOLEŽEL, Zdeněk January 2015 (has links)
This masters thesis deals with renovations expensive spare parts for the use of special engineering technologies. The aim was to compare and evaluate the technical and economical technological processes used components renovations. In the theoretical part are written information obtained from literature sources dealing with the basic concepts, definitions and describes the most commonly used technology renovation. In their study were selected components for renovation, where it is necessary to use special methods of engineering technologies. The first part was chosen balancer shaft used for four-cylinder diesel engine Volkswagen. For component was suggested special technological process of repair, so as to achieve low prices, but also guarantee a high quality repair and threaten further damage. Price repairs were compared against the cost of a new spare part. Another component was selected renovation speed bump for truck Scania. For component was suggested technological process of repair. Prices renovations by various techniques were compared.
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