• Title/Summary/Keyword: quality maintenance

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A Conceptual Procedure of RAMS Centered Maintenance for Railway Systems (철도시스템의 RAMS 중심의 유지보수 정책 결정을 위한 개념적 절차)

  • Kim, Jong-Woon;Park, Jun-Seo;Lee, Ho-Yong;Kim, Jae-Hoon
    • Journal of the Korean Society for Railway
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    • v.11 no.1
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    • pp.19-25
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    • 2008
  • There are two main parts to improve the quality and the efficiency of railway service. One is to acquire the system with high RAMS performance and the other is to keep it up. Therefore we need to specify RAMS requirements in the system specifications and verify them. In addition, it is necessary to monitor RAMS and to make operation and maintenance policies based on RAMS. This article presents RAMS centered maintenance procedure of which target is to continuously achieve the inherent RAMS performance of the acquired system. The method to evaluate the effect on RAMS and the conceptual optimal model for determining maintenance interval are also proposed.

Failure Rate Model of External Environment Maintenance for a System under Severe Environment (가혹환경 하에서 사용되는 시스템의 외부환경보수에 대한 고장률 모형)

  • Park, J.H.;Shin, Y.J.;Lee, S.C.;Lie, C.H.
    • Journal of Korean Institute of Industrial Engineers
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    • v.36 no.1
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    • pp.69-77
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    • 2010
  • The failure rate model of External Environment Maintenance(EEM) for a system under severe environment is investigated. EEM, which is recently introduced concept, is a maintenance activity controlling external environment factors that potentially cause system failure such as cleaning equipment, controlling temperature (humidity) and removing dust inside of electronic appliances. EEM can not have any influence on the inherent failure rate of a system but reduce the severity of the external environment causing failure since it deals with only external environment factors. Therefore, we propose two failure rate models to express the improvement effect of EEM: The intensity reduction model and age reduction model. The intensity and age reduction models of EEM are developed assuming the quality of improvement effect is proportioned to an extra intensity or age respectively. The validation of proposed failure rate models is performed in order of data generation, parameter estimation and test for goodness-of-fit.

A Study on the Privatization of School Facilities Maintenance (학교시설유지관리의 민간위탁에 관한 연구)

  • Cho, Chang-Hee;Lee, Hwa-Ryong
    • Journal of the Korean Institute of Educational Facilities
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    • v.15 no.2
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    • pp.39-49
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    • 2008
  • School facilities maintenance is concerned about providing clean and safe environments for children. It is also about creating a physical setting that is appropriate and adequate for learning. But many of the school buildings in Korea have been maintained and operated by each school manger or pubic officers in the Educational Department. This system could not extend the life of building components, keep equipment functioning as designed or sustain a sage and healthful environment because of its non-professionality and the dual fiscal system. In order to improve such problems, it is proposed to privatize the maintenance of school building. It is sure that the new way to outsource services reduce costs and provide high quality services. Competitive contracting with the private sector can provide schools with expertise, flexibility and cost efficiencies as well as help school administrators focusing on educating the children. This study explores the maintaining status of existing schools, analyses the cases about BTL schools and the foreign country's policies and surveys the outsourcing cases of Kyungki-do schools. Finally it proposes more appropriate plans for privatizing the maintenance way of school building in Korea.

Transmission Characteristics LonWorks/IP-based Virtual Device Network for Predictive Maintenance (예지보전을 위한 LonWorks/IP 가상 디바이스 네트워크의 통신특성에 관한 연구)

  • Choi, Gi-Heung
    • Journal of the Korean Society of Safety
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    • v.17 no.4
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    • pp.196-201
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    • 2002
  • Web-based predictive maintenance (PM) utilizes Virtual Device Network (VDN). VDN inevitably the implementation of Distributed Monitoring and Control Networks (DMCN). In general, one needs to integrate fieldbus protocol and TCP/IP to realize DMCN over IP network or internet, which can be viewed as Virtual Device Network (VDN). Interoperability between devices and equipments is essential to enhance the quality and the performance of predictive maintenance (PM). This paper investigates the transmission characteristics of VDN and suggests a basic framework for web-based PM using DMCN over IP network.

The Impact of the Working Environment and Welfare on Human Resources Maintenance: An Empirical Study in Vietnam

  • KHANH, Vo Thi Van
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.6
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    • pp.447-453
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    • 2021
  • Human resources play a key role in developing and enhancing the manner in which an organization change. In fact, the role of human resource-related quality management has contributed greatly to the growth of the organization in both the short and long term. The purpose of the current study is to identify factors that influence human resource retention in Hanoi in the backdrop of growing economic performance of Hanoi in Vietnam's economy. Primary data was collected through questionnaires of 280 respondents from the four districts in Hanoi, including 25.2% of respondents working in Cau Giay district, 21.2% in Dong Da district, 34.2% in Ha Dong district, and 19.4% in Thanh Xuan district. After applying Cronbach's Alpha and Explore Factor Analysis (EFA) analysis, Durbin-Watson test, empirical results demonstrate that relationship among co-workers has a significant and positive contribution on the maintenance of human resources in the organization. Additionally, higher welfare facilities for an employee are more likely to impact the maintenance of human resources in the organization. Factors such as working environment, job placement, and leadership relationship have no adverse effect on the maintenance of human resources, although a positive impact could be established in all cases.

A Study on the Present Condition about the Management of Repair and Long-term Maintenance Historical Data in the Rental Apartment (임대아파트의 수선 및 장기수선 이력 정보관리에 관한 실태조사연구)

  • Lee Chun-Kyong;Jung Young-Han;Son Sang-Jun;Hwang Young-Sam;Park Tae-Keun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.533-536
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    • 2003
  • Tn improve the quality in apartment houses, it has regarded one of the most important steps as systematic maintenance. Also, repair and long-term maintenance have played an important role in maintenance of the rental apartment. Moreover, the historical data which come from these works have functioned as preventive maintenance in inspection and references in repair and long-term maintenance. To sum up, it would be necessary to get rid of the factors of dispute from sharing a variety of data among occupants, superintendents, and proprietors. Futhermore, it would be possible to show the management methods of repair and long-term maintenance historical data.

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A QUALITATIVE SURVEY ON SUCCESS FOR MAINTENANCE PROJECTS

  • Albert P C Chan;Daniel W M Chan;Edmond W M Lam
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.186-195
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    • 2007
  • Key Performance Indicators (KPIs) are the criteria of measuring project performance in order to attain construction excellence. Previous researchers have examined the abstract concept of success for general new construction and identified its relationship with the factors of success. In fact, most buildings exist to satisfy the needs of people. With the passing of time and change in technology, buildings have to be maintained and renovated in order to continue functioning properly for the benefits of users. Therefore, criteria and factors of success have increasingly attracted the attention of both researchers and practitioners, especially in cities where buildings become ageing. However, the topic of project success for maintenance projects is less discussed in previous research, and project participants, including maintenance surveyors should be able to identify the success measurement and its associated factors for performance improvement. This study fills the research gap by investigating the criteria and factors of success for maintenance projects. It first provides a summary of the literature review on the criteria and factors of success for construction projects. An empirical study has also been carried out with ten practitioners in Hong Kong to further identify the criteria and factors critical for the success of maintenance projects in practice. While most criteria and factors of success for new construction projects are also applicable to maintenance projects, participants in maintenance projects believe that effective communication is in particular important to provide quality service to the end-users.

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Current Situation and Improvement of Indoor Air Quality at University Dormitory (대학교 기숙사의 실내공기환경 실태 및 개선방안)

  • Choi, Lyoung-Hee;Kwon, Oh-Jung
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.251-256
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    • 2009
  • The purpose of this study was to suggest the idea for IAQ improvement of university dormitory through space analysis and residents' evaluation. The data was collected from 105 Konkuk university dormitory residents by a questionnaire survey. As a result, the idea for IAQ improvement of university dormitory can be suggested. First, it was found that it was necessary to improve size of windows and to exchange bathroom exhaust system for ventilation. Secondly, it is important for resident to ventilate and clean their room. Thirdly, the educational program for dormitory residents about maintenance of IAQ was esssentially needed. Also, it is necessary to manage air conditioning equipment maintenance and bathroom hygiene.

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Age Replacement Policy for A System Considering Failure Characteristics of Components (부품(部品)의 고장특성(故障特性)를 고려한 시스템의 수명교환방침(壽命交換方針))

  • Jeong, Yeong-Bae
    • Journal of Korean Society for Quality Management
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    • v.21 no.2
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    • pp.109-120
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    • 1993
  • Most systems are composed of components which have different failure chracteristics. Since the failure characteristics of components is different, it is rational and reasonable to establish a maintenance model to be considered repair and replacement policies which are proper to failure characteristics of these components. This paper proposes the age replacement time for a system composed of components which have different failure characteristics. In this model, it is assumed that a system is composed of a critical failure component, a major failure component, minor failure component. If any failure occurs to critical component before its age replacement time, the system should be replaced. If any failure does not occur until its age replacement time, preventive replacement should be performed at age replacement time T. Major component is minimal repaired if any failure occurs during operation. Minor component should be replaced as soon as failure is found. This paper determines the optimal replacement time of the system which minimize, total maintenance cost and initial stock Quantity of minor component within this optimal replacement time. Numerical example illustrates these results.

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Optimal Preventive Maintenance Policy for a Repairable System (수리 가능한 시스템에서의 최적 예방 보전 정책)

  • Ji Hwan Cha;Jong Tae Jung;Jae Joo Kim
    • Journal of Korean Society for Quality Management
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    • v.29 no.2
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    • pp.46-53
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    • 2001
  • In this paper, a preventive maintenance(PM) policy for a repairable system is considered. The failure rate model proposed by Park et at.(2000) is generalized by assuming that after each PM not only the PM slows down the degradation process of the system but also reduces down the system failure rate by a certain fixed amount. Long-run expected cost rate of the PM policy is derived and the properties of joint solution of the optimal PM period and optimal number of PM which minimizes the expected cost rate are obtained. Numerical examples for the case of a Weibull-type failure rate are given.

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