• 산업경영시스템학회지
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• 제17권30호
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• pp.73-79
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• 1994

This paper propose Adaptive Maintenance as a new type of maintenance for machine failures which are unpredictable. A purpose of adpative maintenance is to decrease inconsistency. In order to pick up some of problems the traditional maintenance policy, We discussed Time Based Maintenance(TBM) and Condition Based Maintenance(CBM) with Bath-Tub Curve. By using Machine Condition Diagnosis Technique (CDT), Monitored condition maintenance deals with the dynamic decision making for diagnosis procedures at maintenance and caution level. Adaptive Maintenance is a powerful tool for Total Production Maintenance(TPM).

• Journal of Information Technology Applications and Management
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• 제29권6호
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• pp.63-80
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• 2022

In this paper, we study structural changes and performance gains in condition-based maintenance process redesign when mobile IoT technology is embedded into urban railway rolling stock. We first develop condition-based maintenance To-Be process model in accordance with the IoT deployment scheme. Secondly, we draw upon theoretical framework of redesign process analysis to develop performance evaluation method suitable to predictive maintenance shift from As-Is ordinary maintenance practice. Subsequently, To-Be process performance evaluations are conducted adopting both the quantitative and qualitative method for time, cost, and dependability dimensions. The results ascertain the considerable benefits captured through detection abnormality prior to actual rolling stock failure occurrence, and details of performance improvements and enhancement of standardization level is revealed. The procedures and results presented in this paper offers useful insights in the fields of IoT economic analysis, condition based maintenance, and business process redesign.

• 한국정보통신학회논문지
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• 제23권7호
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• pp.869-874
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• 2019

노화에 의한 시스템의 예기치 않은 장애 발생은 예방 관리 기능을 수행함으로써 줄일 수 있으며, 이를 통해 시스템의 가용도를 높일 수 있다. 예방 관리 기법은 크게 시간 기반과 조건 기반의 두 가지로 나눌 수 있다. 시간 기반 방식은 정해진 시간 간격마다 수행되고, 조건 기반 방식은 시스템 상태가 특정 조건을 만족할 때 수행된다. 조건 기반 방식은 시간 기반 방식과 비교했을 때 예방 관리의 효율성을 향상시킬 수 있다는 장점이 있다. 본 논문은 노화 상태에서 일정 시간이 지난 후 예방 관리를 수행하게 되는 시스템을 분석할 수 있는 확률 모형을 제시한다. 제시한 모형은 현실적인 상황을 반영하여 비 마르코비안 모형으로 모델링한다. 해당 확률 모형을 수학적으로 해석하여 정상 상태에서의 시스템 가용도와 수익을 분석한다.

• 산업경영시스템학회지
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• 제22권52호
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• pp.171-180
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• 1999

Industrial equipment reliability improvement and maintenance is gaining attention as the next great opportunity for manufacturing productivity improvement. Reactive maintenance is expensive because of extensive unplanned downtime and damage to machinery. To avoid such an unplanned machine downtime, it is needed to use proactive maintenance approach by either using historical maintenance data or by sensing machine conditions. This paper discusses failure diagonosis and prediction based on the condition-based maintenance and reliability technique. Thus, by enabling such a framework, it can bring us more efficient planning and execution of maintenance to reduce costs and/or increase profits.

• 품질경영학회지
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• 제49권3호
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• pp.269-279
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• 2021

Purpose: The purpose of this study was to suggest weapon system specifications for requirements of Condition-Based Maintenance(CBM/CBM⁺). Methods: The military documents and case studies with regard to condition-based maintenance were reviewed. Representative Korea defense specifications of weapon system such as an aircraft, a C4ISR etc. were analyzed and investigated the level of requirement for maintainability was. Results: Condition-based maintenance was defined in both U.S. instruction and Korean directive. While deparment of defense(U.S.) provide a guidebook for CBM⁺, detailed instruction was not sufficient for Korean. Ministry of national defense(ROK) define the CBM⁺ by means of IPS element which should be developed along with the system development. The maintainability was barely included in Korean defense specifications, except for BIT(Built-in test) function. As a first step for defining the condition-based maintenance requirement in defense specification, this study suggests a standard form for data needed to acquire according to types of system, fault, failure, and so on. Conclusion: The empirical researches on CMB/CBM⁺ with domestic weapon systems are not enough, and a logic which leads the maintenance strategy to CMB/CBM⁺ is not solved. Through technical researches and institutional improvements including this study, we hope that condition-based maintenance would be fully established in the Korean defense field.

• 한국압력기기공학회 논문집
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• 제6권1호
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• pp.1-8
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• 2010

The existing maintenance program is focused on time-based maintenance to inspect and repair components according to maintenance period, rather than condition-based maintenance or predictive maintenance. The preventive maintenance template of the steam turbine has been developed for optimizing maintenance procedure and improving reliability and availability of the steam turbine of nuclear power plants based on EPRI PM template methodology and EPRI technical reports about preventive maintenance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.263-269
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• 2012

Condition-based maintenance (CBM) has been used as a useful concept for optimizing maintenance plan and decreasing maintenance cost in several kinds of plant sites. This study introduced an example that developed an integrated management system for maintenance parameters and hydraulic turbine of hydro-power plant in order to improve its maintenance system as applying CBM techinique. The integrated management system consists of three parts. One is a hardware part including PDA inspection system and several kind of precision measuring instruments. Another is a vibration monitoring system on hydraulic turbine. The other is a software part that takes charge of making hierarchy tree of maintenance parameters and their inspection route, managing accumulated database, assessing health condition of components, and supporting interface with other enterprise management system. The system has been installed at Chuncheon Hydro-power plant for test and demonstration. It is expected that the system can contribute database construction for diagnostics and prognostics on facility health condition and systematic accumulation of know-how on operation and maintenance of plant.

• 한국소음진동공학회논문집
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• 제22권6호
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• pp.574-581
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• 2012

Condition-based maintenance(CBM) has been used as a useful concept for optimizing maintenance plan and decreasing maintenance cost in several kinds of plant sites. This study introduced an example that developed an integrated management system for maintenance parameters and hydraulic turbine of hydro-power plant in order to improve its maintenance strategy as applying CBM techinique. The integrated management system consists of three parts. One is a hardware part including PDA inspection system and several kind of precision measuring instruments. Another is a vibration monitoring system on hydraulic turbine. The other is a software part that takes charge of making hierarchy tree of maintenance parameters and their inspection route, managing accumulated database, assessing health condition of components, and supporting interface with other enterprise management system. The system has been installed at Chuncheon hydro-power plant for test and demonstration. It is expected that the system can contribute database construction for diagnostics and prognostics on facility health condition and systematic accumulation of know-how on operation and maintenance of plant.

• KNOM Review
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• 제24권1호
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• pp.13-19
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• 2021

최근 산업 분야에서는 공장 자동화 뿐만 아니라 장애 진단/예측을 통해 고장/사고를 사전에 방지하여 생산량을 극대화하기 위한 연구가 진행되고 있으며, 이를 구성하기 위해 많은 양의 데이터 축적을 위한 클라우드 기술, 데이터 처리를 위한 빅 데이터 기술, 그리고 데이터 분석을 쉽게 진행하기 위한 AI(Artificial Intelligence)기술이 도입되고 있다. 또한 최근에는 장애 진단/예측의 발전으로 인해 설비 유지보수(PM: Productive Maintenance) 방식도 정기적으로 설비를 유지보수 하는 방식인 TBM(Time Based Maintenance)에서 설비 상태에 따라 유지보수 하는 방식인 CBM(Condition Based Maintenance)을 조합하는 방식으로 발전하고 있다. CBM 기반 유지보수를 수행하기 위하여 설비의 상태(condition)의 정의와 분석이 필요하다. 따라서 본 논문에서는 머신 러닝(Machine Learning) 기반의 장애 진단을 위한 시스템 및 데이터 모델(Data Model)을 제안하며, 이를 기반으로 장애를 사전 예측한 사례를 제시하고자 한다.

• 한국압력기기공학회 논문집
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• 제7권2호
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• pp.7-13
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• 2011

Turbine journal bearings are designed to support the weight of the rotors on a hydrodynamic oil film and to provide dynamic stability to the rotor system. The life time of journal bearings is infinite theoretically because the journal bearings are separated from the shaft journal by oil film. But poor design, assembly, operation and maintenance can cause problems to the journal bearings. The FMEA(Failure Mode and Effects Analysis) results of the journal bearings show that frequent maintenance of the journal bearings can cause failures and reduction of the bearing life. Therefore, the maintenance periods and history of the journal bearings with the bearing FMEA results are reviewed in order to establish the optimized maintenance period of the journal bearing for the nuclear power plants. Consequently it is necessary to maintain a best condition of lubrication system, reject time-based maintenance and perform the condition-based maintenance of journal bearings in order to maintain optimum condition of the journal bearing.