• Proceedings of the KSR Conference
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• 2007.11a
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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.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.3
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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.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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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.

• Proceedings of the KSR Conference
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• 2009.05b
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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.

• Journal of Applied Reliability
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• v.15 no.4
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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.

• IE interfaces
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• v.18 no.4
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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.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.651-659
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• 2012

Target operational availability setting is the first step to setting up a goal which a weapon system development project have to achieve and doing RAM analysis during whole life of a weapon system. It is important as a key factor to doing RAM analysis in the early phase of weapon system development. This paper present a methodology to set a target operational availability for, especially, a warship when it develop. This methodology uses Operational Mode Summary/Mission Profile(OMS/MP) of the developing warship and RAM analysis results of similar warships to calculate wartime and peacetime target operational availability. It will be used in early phase of not only warship development but also army or aircraft weapon systems when these develop.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.505-510
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• 1996

A simple model for RAM (Reliability, Availability and Maintainability) analysis and its computer code are developed for application to DUPIC fuel fabrication system. The approach is obtained by linking the allocation model (top-down method) to bottom-up method for RAM analysis. As a result, the availability requirement of subsystem, as well as the buffer storage requirement between processes, are evaluated for the DUPIC facility..

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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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.

• Journal of Applied Reliability
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• v.17 no.2
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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.