• 한국IT서비스학회지
• /
• 제9권4호
• /
• pp.169-185
• /
• 2010

According to software growth, also software maintenance has been continuously improving. In addition, the existing concept of software maintenance process demands operational management and improvement of service task. However, when we perform maintenance task, we have several constraints about applying service based requirement to system. Therefore, in order to solve these problems, we need a study of task of process for service based maintenance. In this paper, we propose a Service based Software Maintenance Process. Proposed process based on MaRMI-RE standard for software development and maintenance and compares it with the service based representative standards. In a related works, we study activity of ITIL and identify activities and tasks for maintenance. After this, identified activities and tasks compare with activities of MaRMI-RE. And then, we derive activities and tasks of a Service based Software Maintenance Process. Finally, we validate a result by comparing the proposed process with a general service operational process.

• 한국IT서비스학회지
• /
• 제8권1호
• /
• pp.99-111
• /
• 2009

Rapid growth of Management Information System (MIS) and evolution of software system enlarge maintenance necessity and it needs a process to implement information system service in business. This paper proposes service-oriented maintenance process of component software based on service design and implementation provided by existing processes for maintenance, MaRMI-RE and ITIL. The proposed process derives activities and tasks of the process by identifying services according to service guidelines. Service-oriented maintenance process is produced by analyzing correlation between the derived activities and tasks and MaRMI-RE's and adding the tasks to MaRMI-RE. To verify availability of the proposed service-oriented maintenance process, correlation between artifacts is proved.

• 대한인간공학회지
• /
• 제36권5호
• /
• pp.559-568
• /
• 2017

Objective: The aim of this study is to investigate the effective managerial factors influencing dose reduction of the nozzle dam installation and removal tasks ranking within top 3 in viewpoint of average collective dose of nuclear power plant maintenance job. Background: International Commission on Radiation Protection (ICRP) recommended to reduce unnecessary dose and to minimize the necessary dose on the participants of maintenance job in radiation fields. Method: Seven sessions of nozzle dam installation and removal task logs yielded a multiple regression model with collective dose as a dependent variable and work time, number of participants, space doses before and after shield as independent variables. From the sessions in which a significant reduction in collective dose occurred, the effective managerial factors were elicited. Results: Work time was the most important factor contributing to collective dose reduction of nozzle dam installation and removal task. Introduction of new technology in nozzle dam design or maintenance job is the most important factor for work time reduction. Conclusion: With extended task logs and big data processing technique, the more accurate prediction model illustrating the relationship between collective dose reduction and effective managerial factors would be developed. Application: The effective managerial factors will be useful to reduce collective dose of decommissioning tasks as well as regular preventive maintenance tasks for a nuclear power plant.

• 시스템엔지니어링학술지
• /
• 제12권1호
• /
• pp.41-58
• /
• 2016

Reliability Centered Maintenance (RCM) introduces a systematic method and decision logic tree for utilizing previous operating experience focused on reliability and optimization of maintenance activities. In this paper RCM methodology is applied on safety injection system for APR-1400. Functional Failure Mode Effects and Criticality Analysis (FME&CA) are applied to evaluate the failure modes and the effect on the component, system and plant. Logic Tree Analysis (LTA) is used to determine the optimum maintenance tasks. The results show that increasing the condition based maintenance will reduce component failure and improve reliability and availability of the system. Also the extension of the surveillance test interval of Safety Injection Pumps (SIPs) would lead to an improved pump's availability, eliminate the unnecessary maintenance tasks and this will optimize maintenance activities.

• 시스템엔지니어링학술지
• /
• 제9권1호
• /
• pp.65-84
• /
• 2013

This paper introduces a systems engineering approach to reliability centered maintenance to address some of the weaknesses. Reliability centered maintenance is a systematic, disciplined process that produces an efficient equipment management strategy to reduce the probability of failure [1]. The study identifies the need for RCM, requirements analysis, design for RCM implementation. Value modeling is used to evaluate the value measures of RCM. The system boundary for the study has been selected as containment spray pump and its motor drive. Failure Mode and Criticality Effects analysis is applied to evaluate the failure modes while the logic tree diagram used to determine the optimum maintenance strategy. It is concluded that condition based maintenance tasks should be enhanced to reduce component degradation and thus improve reliability and availability of the component. It is recommended to apply time directed tasks to age related failures and failure finding tasks to hidden failures.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.784-791
• /
• 2007

Most operational organization and railway authority which conduct scheduled maintenance(SM) have carried out the preventive maintenance(PM) based on the information provided from supplier and manufacturer of railway system. However these activities are far away from reality and low the efficiency, it is because an appropriate methods for system selection didn't take into account for improving maintenance efficiency. Therefore, the current SM tasks and maintenance activities lead to lots of spend on the cost and time. To solve the above problem, this thesis presents new approach methodology. This proposes the criteria for reliability centered maintenance(RCM) system selection through level of quantification of each parameter, i.e, frequency, severity and maintenance cost, etc. To do this, the field operation data and information of maintenance cost are essential. As applying this methodology, we can look forward to improving efficiency of PM/SM, and reducing cost.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.1520-1524
• /
• 2004

This paper describes the development of a robotic maintenance system for use in a maintenance operation of the nozzle dam in a water chamber of a steam generator at the Kori nuclear power plant in Korea. The robotic maintenance system was designed to minimize the personnel exposure to a hazardous radioactive environment. This robotic maintenance system is operated by a teleoperated control which was designed to perform the nozzle dam maintenance tasks in a remote manner without endangering the human workers. Specific maintenance tasks involve the transportation, insertion, and removal of nozzle dams in a water chamber inside a steam generator via a narrow man-way entrance port. The developed robotic maintenance system has two major subsystems: a two degrees of freedom guiding device acting as the main guiding arm and a master-slave manipulator with a kinematic dissimilarity. The mechanical design considerations, control system, and capabilities of the robotic maintenance system are presented. Finally, a graphical representation of the nozzle dam maintenance processes in a simulated work environment are also demonstrated.

• 한국항행학회논문지
• /
• 제26권6호
• /
• pp.373-379
• /
• 2022

KASS (korea augmentation satellite system)는 국제민간항공기구 (ICAO; international civil aviation organization)의 항공통신 관련 국제표준권고 (SARPs Annex 10)에 따른 항공용 서비스 성능이 보장되어야 하는 한국형 SBAS (satellite based augmentation system) 이다. 목표 서비스 성능의 보장을 위해서는 운영 시스템이 안정적으로 동작하고 유지, 관리되어야 하며 이를 위해 유지보수 체계가 확립되어야 한다. 유지보수 관점에서 KASS 하위시스템을 교체유닛 단위로 정의하고 유지보수 조직, 유지보수 절차를 정의하였다. 또한, 유지보수 수행을 위한 교체유닛 단위의 유지보수 임무를 산출하였으며 산출된 임무가 앞서 정의된 교체유닛 단위를 충분히 포괄하는지 검증하였다. 본 연구를 통해 산출된 유지보수 임무는 2023년 말 본격적인 항공용 서비스 제공 전, 실 운영 준비과정에서 검증될 것이며 지속해서 업데이트될 것이다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.38-46
• /
• 2011

Recently railway operators are doing a lot of researches and studies in order to apply reliability technologies to their maintenance tasks. The maintenance in the aviation and the munitions industry has been developed enough to be benchmarked with the high quality reliability technologies; however, railway industry is still situated in a rudimentary stage with insufficient & limited data. 5678 Seoul Metropolitan Rapid Transit Corporation, which has 17 year experience of the EMU maintenance and system development, has made a constant effort for appling RCM (Reliability Centered Maintenance) to the maintenance for a few years. In this connection, the case study is to be introduced. This paper is based on 'RCM Gateway to World Class Maintenance' by Anthony M. Smith". The reliability technology are applied to the specific EMU and its system by 7 stages; accordingly, applying SMRT's maintenance experience, a unique standard for FMEA(failure mode effect analysis) & LTA(logical tree analysis) is established. Moreover, for reasonable and effective preventive maintenance tasks, the case considering an analysis of failure effects is selected in the final step 7. SMRT will develop reliability technologies through the application of the results to all the EMU systems.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
• /
• 제14권1호
• /
• pp.81-85
• /
• 2008

객체지향 패러다임에서 커플링은 유지보수활동에 가장 큰 영향을 주는 속성 중 하나로 많은 연구들이 진행되어 왔다. 그러나 기존의 커플링 척도는 클래스들간의 의존성 여부만 측정할 뿐 의존성 강도를 표현하지 못하기 때문에 리팩토링이나 시스템 분해와 같이 의존성 강도 정보가 필요한 유지보수활동에서 의사 결정을 지원하는데 한계가 있다. 이 논문에서는 이를 해결하기 위해 클래스 간의 의존성 여부뿐만 아니라 유지 보수성-재검사 비용 측면에서 클래스 간의 의존성 강도까지 표현할 수 있는 커플링 척도를 제안한다. 그리고 시스템 분해 문제에 적용한 예제를 통하여 시스템 유지 보수를 위한 여러 분야에 적용될 수 있음을 보인다.