• Journal of Information Technology Services
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• v.9 no.4
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• pp.169-185
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• 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.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.99-111
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• 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.

• Journal of the Ergonomics Society of Korea
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• v.36 no.5
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• pp.559-568
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• 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.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.1
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• pp.41-58
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• 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.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.1
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• pp.65-84
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• 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.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.784-791
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• 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
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• 2004.08a
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• pp.1520-1524
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• 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.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.373-379
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• 2022

KASS (korea augmentation satellite system) is an SBAS (satellite based augmentation system) that must ensure the performance of aviation service in accordance with the International Civil Aviation Organization's SARPs (standards and recommended practices) Annex 10 - Aeronautical Telecommunications. In order to guarantee the target service performance, the operating system must be operated, maintained and managed stably, and a maintenance system must be established for this purpose. From the maintenance point of view, the KASS subsystems were developed to consist of replacement units, and the maintenance organization and procedures to manage those subsystems and units were defined. In addition, the maintenance task for each the replacement unit was developed to ensure the availability performance required for the successful KASS operation, and the developed tasks were verified to sufficiently cover the activities to maintain the previously defined replacement units. The maintenance tasks developed through this study will be continuously verified in the actual operation preparation process prior to the full-scale provision of aviation services in the end of 2023, and will be updated accordingly.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.38-46
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• 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.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.1
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• pp.81-85
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• 2008

The coupling measurements of object oriented programs can be valuable information for various maintenance tasks and there exists a variety of metrics proposed by numerous researchers. Those metrics, however, cannot measure the strength of dependencies between classes, but only imply the existence of dependencies. Hence they are of limited value for assisting maintenance tasks such as refactoring and system decomposition, which requires information about the strength of dependency. In this paper, a coupling metric which can measure the strength of dependence as well as detect the existence of dependencies is proposed. Our coupling metric is evaluated based on the cost required for performing the maintenance tasks. We have applied the proposed coupling metric to an example of system decomposition in an effort to assess the potential benefits of our approach for maintenance tasks.