Fuzzy maintenance costs of a wind turbine pitch control device

This paper deals with the problem of estimation maintenance costs for the case of the pitch controls system of wind farms turbines. Previous investigations have estimated these costs as (traditional) “crisp” values, simply ignoring the uncertainty nature of data and information available. This paper purposes an extended version of the estimation model by making use of the Fuzzy Set Theory. The results alert decision-makers to consequent uncertainty of the estimations along with their overall level, thus improving the information given to the mainte-nance support system.Fundação para a Ciência e Tecnologia (FCT), Project: FCOMP-01-0124-FEDER-02267

A Study on the Mode of Introducing Independent Maintenance into Traditional Industries That Rely on Manual Work

The vast majority of Taiwan's enterprises are small and medium-sized enterprises, which account for 98% and mostly are built up by the traditional industry. But along with the technical progress and development of production technology, the traditional industry is faced with survival bottleneck because of high cost and various competitors. Therefore this research aims to explore the mode of introducing independent maintenance to traditional industries, and to develop a suitable one for today's traditional industries. Research results will be provided to the domestic traditional industries for reference in order to reduce the cost and difficulty they may have in importing independent maintenances

Una aplicación multi-criterio para la decisión de reemplazar un equipo

AbstractOne of the main problems, in the operations management, is the adequate planning of equipment replacement, not only because of its impact in the operations cost, but also, because of its effects on the service level. For such reason, the present article shows the construction of a procedure for equipment replacement, based on the use of multicriteria techniques and expert methods. The results of this application, in the replacement decision of two equipments for a sugar factory, are presented.ResumenUno de los principales problemas, en la dirección de operaciones es laadecuada planificación para el reemplazo de los equipos, no solamente por su impacto sobre el costo de las operaciones, sino también por sus efectos sobre el nivel de servicios. Por esta razón, el presente artículo muestra la construcción de un procedimiento para el reemplazo de equipos, basado en el uso de técnicas multicriteriales y métodos expertos; los resultados de esta aplicación en la decisión de reemplazar dos equipos para una fábrica de azúcar se muestran a continuación

Criticality evaluation to support maintenance management of manufacturing systems

This paper focuses on criticality evaluation for supporting daily equipment maintenance management and the definition of medium and long-term maintenance actions to improve equipment and, therefore, productivity. These two different purposes led to the development of two different methods for criticality evaluation, using criteria adjusted for each case. The first method is based on rules for defining priorities for corrective and preventive maintenance tasks. Since a failure mode of critical equipment is not necessarily critical, priorities for maintenance tasks are assigned to tasks rather than to equipment. The second method uses Analytic Hierarchy Process to prioritize equipment based on its performance. This method is based on the indicators commonly monitored by maintenance departments. In addition to assessing equipment performance, it considers the maintenance effort made to achieve the evaluated performance. The selection of the criticality criteria and the development of the methods was based on literature review and triggered by a case study in a multinational automotive company. With the integration of the proposed methods in a computerized maintenance management system, maintenance technicians and managers are able to know in real time the tasks that should be performed first and to monitor the overall performance of equipment in the plant, focusing improvements where they are more required.POFC - Programa Operacional Temático Factores de Competitividade (UID/CEC/00319/2013

Abordagem processual em projetos de Parada Total de Produção: estudo dos benefícios na gestão da manutenção / Procedural approach in projects of Total Stop Production: study of benefits in maintenance management

 Apesar de sua importância para manter a segurança e a confiabilidade no funcionamento das fábricas, as atividades de manutenção são muitas vezes vistas apenas como despesas e empecilhos para a produção. Em casos em que é necessário efetuar serviços que exigem a parada total da produção, os custos são especialmente elevados e é necessária uma gestão da manutenção eficiente que faça os reparos corretamente e no menor tempo possível, evitando perdas não planejadas. Normalmente essas paradas são gerenciadas por projetos que se destacam por deslizes de custos e cronograma. Todo o planejamento, execução e controle dessas atividades executadas nos projetos, porém, apresenta características similares aos processos de manutenção de rotina. Este artigo propõe identificar ações da gestão por meio de uma abordagem processual capazes de proporcionar melhor desempenho na gestão da manutenção em projetos de parada total de produção. Para tanto, realizou-se levantamento na literatura especializada e pesquisa de campo em uma multinacional do setor de mineração, onde foram coletados dados através de análise dos processos existentes e em entrevistas com gestores. Os dados foram confrontados com a abordagem conceitual existente na gestão da manutenção, gerando os resultados descritos neste artigo, que apresentam importantes benefícios que poderiam ser obtidos pela abordagem processual.

Systematization of sustainability indicators as a tool to assist in the selection building materials by the project designer

O processo de especificação de materiais de construção exige dos profissionais um conhecimento cada vez mais amplo, e, quando correlacionada ao conceito de sustentabilidade, a sistematização de indicadores torna-se uma ferramenta de fundamental importância para a escolha responsável dos materiais construtivos. Esta pesquisa teve por objetivo sistematizar os indicadores potencialmente aplicáveis em um processo de seleção de materiais de construção com base na sustentabilidade. Para a definição dos mesmos foram adotadas como referências as principais ferramentas de avaliação de sustentabilidade, e, para o estabelecimento do alicerce conceitual, foram consideradas as fontes com reconhecida confiabilidade, oriundas principalmente de livros e artigos científicos nacionais e internacionais. A partir da sistematização, foi efetuada a correlação dos indicadores com as dimensões ambiental, econômica, social e cultural do conceito de sustentabilidade. Também foi feita uma análise complementar apontando as etapas do ciclo de vida em que os indicadores atuam para que a sustentabilidade seja favorecida. Como resultado principal, foram listados e conceituados 33 indicadores, sendo perceptível a maior relação dos indicadores com a dimensão ambiental da sustentabilidade. Também foi possível verificar que os indicadores se correlacionam de forma proporcional com as etapas do ciclo de vida, com exceção da etapa Uso/Operação, visto que nesta ocorre menos manipulação do material.Palavras-chave: indicadores de sustentabilidade, materiais de construção, seleção de materiais.The process of specifying construction materials requires from professionals an increasingly broad knowledge and, when correlated to the concept of sustainability, the systematization of indicators becomes a tool of fundamental importance for the responsible choice of building materials. This investigation aims to systematize the indicators potentially applicable in a process of selection of building materials based on sustainability. For the definition of these indicators we adopted the main tools for sustainability assessment as references. For the establishment of the conceptual foundation we considered the sources with known reliability, mainly from national and international books and scientific papers. On the basis of the systematization, we established the correlation between the indicators and the environmental, economic, social and cultural dimensions of the concept of sustainability. We also made a complementary analysis pointing out the stages of the life cycle in which the indicators help to favor sustainability. As a major result, 33 indicators were listed and appraised, where a greater relation of the indicators with the environmental dimension of sustainability can be noticed. It was also observed that the indicators are correlated in a proportional manner with the stages of the life cycle, with the exception of the Use/Operation step, in which there is less manipulation of material.Key words: sustainability indicators, building materials, materials selection

Fuzzy Logic Based Smart Grid for Power System Application

Smart grid manages the innovation for modernizing power flow frameworks by exploitation circulated and PC based remote detecting, administration and robotization, and two-way correspondences. Potential edges of the innovation region unit that the great grid's focal administration can right now have the capacity to administration and work a few remote station, streamline the general quality use and operational speedily. Amid this paper, there is an inventive methodology for the great framework to handle vulnerability emerging from condition perception and support of force plant. The mentality utilizes optional versatile support advisor and a framework upkeep analyser for outlining/executing streamlined condition-based protection happenings, and together handles [2] operational dissimilarities happening in every station. The framework upkeep enhancer creates the starting support anticipates each station with multi objective enhancement by taking into consideration just the look or normal operational conditions.[2] Amid methodology, the station can experience ageing, administration movements, moving climate and payload components, and shaky estimations. Living on every host station, the upkeep advisor can survey the capacity of beginning support arranges; and gauge the obligation changes created by effective dissimilarities on the substation utilizing a hierarchal fuzzy framework. The consultant determination caution the preservation streamlining agent on regardless of whether a reoptimization of its support exercises should be started for meeting the general framework dependability request.[7]. Mean time between failure (MTBF) and mean time to failure (MTTF) are studied in this thesis and fuzzy logic is generate to find he MTTF and MTBF, such that the components that present in the grid may be maintained from time to time without any failure in the system

An Evaluation of the Impacts of Replacement Reserve Studies on the Stewardship of Historic Houses of Worship

Reserve studies are a facilities maintenance planning tool created by the common interest development industry in the United States that could be a useful tool for heritage site managers to financially plan for maintenance and repairs. Unexpected building related costs can be a threat to the financial stability of religious organizations and other types of nonprofits housed in historic buildings because these organizations require lead time to raise funds. Reserve studies could be a useful tool for site managers to financially prepare plan for repairs and generate realistic reserves to cover future expenditures. Reserve study reports include a physical assessment of an organization’s facilities and a funding plan to provide income to a reserve fund to offset maintenance and repair expenditures for a minimum of twenty years. This thesis explores the potential for reserve studies to help religious organizations and other nonprofits housed in historic buildings accurately estimate and provide for facilities maintenance to become more financially sustainable organizations. Evidence for this thesis was sourced from interviews with five stewards of religious buildings of differing ages that are at various stages of implementing recommendations made by reserve studies. Comparing the experience of stewards of recently constructed buildings to historic buildings explores the effect of building age on the use of reserve studies

Análise da fiabilidade e melhoria do processo de fabrico: Estudo de caso em uma fábrica de componentes para automóveis

A condução atual dos negócios, considerando uma economia globalizada e altamente competitiva, necessita de mudanças na mentalidade e posturas do setor industrial. O conceito de que a função da manutenção é restabelecer as condições originais dos equipamentos está ultrapassado. Na visão atual, a manutenção deve ser organizada, e deve evitar as ocorrências dos eventos de falha, objetivando reduzir custos industriais e maximizar a produtividade de máquinas e equipamentos. Face ao exposto, o seguinte estudo deseja abordar com prontidão e de forma proactiva, a melhoria e optimização do processo de uma linha de produção específica, por meio do gerenciamento estratégico das atividades da manutenção. Este trabalho tem por finalidade estudar e analisar o comportamento da fiabilidade de um sistema industrial, visando obter informações para gerir as atividades da manutenção de uma maneira mais eficiente, propiciando a contenção de falhas e o aumento da disponibilidade operacional dos equipamentos produtivos. Após a execução do estudo, pode-se concluir que as análises de falhas e da fiabilidade da linha foram essenciais para auxiliar na adequada seleção da estratégia de manutenção a ser adotada, e para a prevenção de falhas. Buscou-se ao invés da eliminação de todos dos problemas, agir criando um programa de ação para os problemas mais críticos, o que levou a diminuir rapidamente o número de ocorrência de falhas.The today’s business driving, considering a globalized and highly competitive economy, requires changes in the mentality and attitudes of the industrial sector. The concept that the maintenance function is just to restore the original equipment conditions is overpast. In the current view, maintenance must be organized, and must avoid the occurrence of failure events, in order to reduce industrial costs and maximize the productivity of machines and equipment. Considering that the following study intends to promptly approach in a proactive way the improvement and optimization of the process of a specific production line through the strategic management of the maintenance activities. This work aims to study and analyze the reliability behavior of an industrial system, and use this information to manage maintenance activities in a more efficient way, aiming to contain failures and increase the operational availability of the machinery. After this study, it can be concluded that failure and reliability analysis were essential to assist the proper selection of the maintenance strategy that should be adopted and to prevent failures. It can also be concluded that, instead of seeking to eliminate all of the problems found in the production line, choosing to create a program of action for the most critical problems has led to a rapid decrease in the number of failures occurrences