• International Journal of Reliability and Applications
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• 제2권4호
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• pp.269-280
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• 2001

The objective of this paper is to provide a model for effective implementation of costing RAM management in the design and procurement of production facility considering the system cost-performance trade-off. This research proposes a two-step approach of costing RAM design and test of system RAM for production facility. In Step 1, a static model is proposed to find an initial system configuration to meet the required performance based on system RAM and LCC and analyzes the trade-off relationships between various factors of RAM and LCC. In the second Step, we developed time and failure truncated models for system reliability test and analysis. For the computational purpose, we developed computer programs and have shown the sample results. By the sample test run, the proposed model has shown the possibilities to provide a good method to analyze system performance evaluation for both design and operational phase, This model can be applied to a wide variety of systems not only for costing RAM of the production facilities but also for the other kinds of equipment.

• 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.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.513-520
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• 2001

신규개발장비에 대하여 사용자가 제시한 RAM-D 요구조건을 만족하기 위한 하부 체계의 RAM-D 설계목표 설정 절차 및 방법에 대하여 기동무기체계의 대표적 장비인 전차를 대상으로 연구하여 RAM-D 요소별 할당 모델을 개발하였다.

• 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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• 제17권2호
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• pp.150-158
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• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2001년도 정기학술대회
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• pp.503-511
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• 2001

신규 개발되는 기동장비의 RAM-D 요구조건 설정방법에 관하여 기동 무기체계의 대표적 장비인 전차를 대상으로 연구하였으며, 사용자의 장비운용에 대한 요구 가용 능력 및 운용유지 조건을 고려한 RAM-D 요구조건 설정절차 및 분석 모델을 개발하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.258-263
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• 2005

The purpose of this research is to present a practical method for efficiently monitoring a reliability growth process using AMSAA(Army Materiel Systems Analysis Activity) reliability growth model. The presented method is viable for identifying failure modes, incorporating design changes and monitoring reliability progress on an on-going basis during the early stages of a product development program. According to the Application Guide for EN 50126(RAM part for Rolling Stock), reliability growth monitoring is essential part of the main tasks of design phase in RAM growth monitoring. Implementation of reliability growth management program will provide very useful information on concept selection, product/process reliability, and cost effectiveness without too much time, money and engineering effort being spent on the development of failure suspect parts.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.255-261
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• 2007

In this paper we introduce the method, procedure and result of RAM prediction for interlocking system which is applied for AREX signaling system. For RAM prediction, we breakdown the interlocking system to the LRU level and select the LRUs of which failure can cause the service delay. The prediction of reliability is based on the Reliability Block Diagram which is the functional diagram composed of selected LRUs and finally, the availability of interlocking system is estimated from the combination of reliability and maintainability.

• 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.

• 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.