• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.191-196
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• 2007

This paper is reviewed RAM(Reliability, Availability and Maintainability) data table utilized for RAM data management to Urban Maglev Transit. As railway systems become more complex, the RAM requirements are reinforced to ensure that a design meets Reliability, Availability, Maintainability criteria. Therefore, it needs the efficient management for RAM data of railway system to meet RAM target. At this study, RAM data management format is suggested to ensure reliability and maintainability based on acquired experience for overseas rolling stock. This RAM data table and FMECA(Failure Mode Effect Criticality Analysis) table are useful to the calculation of MTBF(Mean Time Between Failure), MTBSF(Mean Time Between Service Failure) and Maintainability. Also, this RAM management table will be efficient to improve the RAM evaluation to Urban Maglev Transit.

• 한국철도학회논문집
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• 제11권4호
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• pp.390-397
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• 2008

정량적 RAM(Reliability, Availability, Maintainability)은 철도차량의 품질을 나타내는 중요한 척도중 하나이다. 국내외의 철도차량 구매사양서에서는 정량적 RAM 요구조건이 제시되고 있으며 이에 대한 달성과 입증을 요구하고 있다. 본 연구에서는 철도차량의 정량적 RAM의 목표값을 설정하는 방법을 서비스 신뢰도, 로지스틱 신뢰도, 운영가용도와 성취가용도 또는 고유가용도, 유지보수성 측면에서 제안한다. 그리고 이 설정방법을 실제 철도차량 운영데이터에 적용해 보았다.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.282-288
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• 2015

Purpose : The purpose of this study is to compare the RAM (reliability, availability and maintainability) value in the acquisition phase with operational period for air weapon systems. The objective is to determine if the value of RAM is sufficient in the field, and look for any difference from the target value to some extent. Methods : For a case study, the ${\bigcirc}{\bigcirc}$ training aircraft is selected. Data from the two acquisition sources are utilized. One is the operational data in domestic aircraft through research and development, and the other is the data from imported aircraft. The two different sources were collected independently and distinctly. Results : According to the analysis, the domestic aircraft shows high deviation in RAM value compare to the imported systems. This is due to the effort of continuous reliability improvement. In the aspect of maintainability, the result shows a slight deviation, and the availability meets the requirement. Conclusion : The results of this study can be used in finding a way that can be effectively applied to the sustainability in the weapon system. If the RAM performance is significantly lower than the target value, then it is necessary to improve the design activities so that they can achieve the RAM target value.

• 품질경영학회지
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• 제39권3호
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• pp.353-364
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• 2011

RAM(Reliability, Availability and Maintainability) is one of the important indicators to show the performance of weapon systems. For analyzing RAM characteristics, RAM simulation is useful and powerful as mathematical techniques. However, it is necessary to build the simulation model to express about the operation environment of weapon systems, and obtain detail input data for reliability and maintainability about the system to get accurate results by RAM simulation. In this paper, we propose a procedure to analyze RAM of the searching system consisting in weapon systems by RAM simulation and we estimate searching system availability by a commercial simulation program, AvSim.

• 한국군사과학기술학회지
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• 제11권6호
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• pp.102-116
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• 2008

In the development stage of weapon system, it is important to analyze RAM(Reliability, Availability and Maintainability) characteristics. RAM simulation is one of the advanced techniques for analyzing RAM to overpass the limit of mathematical techniques. However, it is necessary to obtain correct input data for reliability and maintainability about target and support system to get highly accurate results through RAM simulation. In this study, we propose the technical method to improve the results by defining input data of simulation more correctly based on analyzing effects of RAM characteristics by major factors.

• 한국국방경영분석학회지
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• 제27권1호
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• pp.58-72
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• 2001

This research deals with the weapon system RAM which is the reliability, availability and maintainability for weapon systems. This weapon system RAM is one of very important factors because it is related to the life cycle cost and combat readiness of weapon systems. Therefore, in this research we introduce the weapon system RAM and analyze the problems of weapon system RAM management during system life cycle including acquisition period. Finally we suggest an alternative to improve the weapon system RAM in various agencies which are the department of defense and army headquarter level, etc., in the process of defense acquisition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.191-198
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• 2009

There are almost no studies on verification of requirements for high speed rolling stocks by means of RAM goals and on setting RAM goals by means of verification on practical reliability, availability and maintainability for high speed rolling stocks though they are covered in specification of an order that RAM goals asked of rolling stocks are shown for gaining high quality of them and availability when they are in operation. This study is for estimating number of high speed train-sets that would be supplementarily placed an order through verification of RAM goals of a project for the introduction of KTX-II 100 cars. It verify that optimized requirements for high speed rolling stocks by relatively comparison with between requirements for train-sets through setting RAM goals and requirements for train-sets through analysis of prospects for management balance with high speed rolling stocks.

• 산업경영시스템학회지
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• 제32권3호
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• pp.127-134
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• 2009

RAM(Reliability, Availability, Maintainability) is important performance factor to keep combat readiness and optimize operational and maintenance cost of weapon systems. This paper discusses the method to establish RAM for combat readiness by using field failure data from similarity equipments. Operational availability is estimated from a binomial distribution function of user's operational conditions such as combat readiness preservation probability, operational rate, operational availability and total number of equipment. Reliability and maintainability is estimated from field failure data from similarity equipment to accomplish operational availability. The effectiveness of established RAM is verified through analysis of combat readiness preservation probability and mission reliability. A case study of weapon system illustrates the process of the proposed method.

• 산업공학
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• 제18권4호
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• pp.477-484
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• 2005

This paper is concerned with the life-cycle cost(LCC) of the urban transit system which was developed by KRRI and is now under test in Gyeongsan, Korea. Its reliability, availability and maintainability(RAM) were analyzed. LCC is the core part of analyzing the total cost of acquisition and ownership of a system. LCC analysis of a system is the most effective when it is applied in the it's early design phase. In this paper, we present IEC 60300-3-3(Life Cycle Costing) in detail and propose how to apply LCC in assessing the urban transit system according to RAM process. This case study demonstrates that reliability management system is very effective in reducing the operating cost of subway corporations in Korea.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1473-1480
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• 2008

본 연구는 현장 운영데이터 분석을 통한 도시철도차량 도어장치의 RAM(신뢰성, 가용성, 유지보수성) 성능 평가 사례를 다룬다. 이를 위하여 도어장치의 고장을 분류하고 정의하며, 각 고장 범주별 신뢰도를 운영 데이터를 통해 분석한다. 유지보수성 평가를 위해서 유지보수 전문가를 통해 LRU(Line Replaceable Unit)를 분류하고 LRU별 교환시간의 추정하여 도어시스템의 평균수리시간을 추정한다. 도어시스템의 가용도는 분석된 신뢰도 및 유지보수성을 기반으로 분석한다. 본 연구에서 제시하는 도어 시스템의 RAM 평가 사례는 도어시스템의 적절한 RAM 요구조건의 수립과 운영단계의 RAM 성능 향상을 위한 정책 수립으로 이어질 수 있을 것으로 기대된다.