• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.12B
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• pp.2016-2024
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• 2000

본 논문에서는 결함의 영향을 받지 않고 동작할 수 있는 AVTMR(All Voting Triple Modular Redundancy) 시스템을 개발하였으며, MILSPEC-217F에 기반을 둔 고장율을 계산하여 AVTMR과 SS(Single System) 시스템을 비교 및 평가하였다. 설계된 시스템은 MC68000을 기반으로 한 3중화된 다수결 보터(Triplicated Majority Voter)를 이용하여 시스템을 개발하였다. 본 논문에서는 시스템의 신뢰도(Reliability), 가용도(Avaliability), 유지보수도(Maintainability)를 마코브 모델(Markov model)로 평가하였으며, 또한 시스템의 MTTF(Mean Time to Failure)를 계산하여 시스템의 수명을 구하였고, 설계된 AVTMR 시스템이 SS(Single System)보다 전체 시스템 평가에서 우수한 특성을 가진다는 것을 시뮬레이션을 통해 알 수 있었다. 또한, AVTMR 시스템은 결함을 허용(Fault tolerant)하는 시스템 특성을 가지기 때문에, 인간의 생명과 관련된 철도 시스템, 선박 시스템이나 항공기 시스템에 적용될 수 있다.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.218-230
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• 2000

In the weapon system development/operation stage, the goals of RAM activities are to support the cost effective performance optimization in design and operation supports. In the study, the main contents are as follows; 1) To establish the operational concept and circumstance of the subsequent tank, the combat/operation scenario, the operational mode summary and mission profile for subsequent tank development are analyzed. 2) To evaluate the administrative and logistics down time for subsequent tank, the prefigured logistics circumstance and maintenance system are analyzed. 3) To calculate the RAM object values, a mathematical model for the user are developed. 4) To examinate the propriety of the RAM object values, the combat readiness are reviewed. The obtained RAM object values are provided to predict and analyze for the combat readiness, staying power, mission reliability, equipment availability and the logistic support capability.

• 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 KSR Conference
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• 2007.11a
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• pp.683-688
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• 2007

The importance of reliability and safety, recently, shows a tendency to increases in railway system constructions and projects. At the point of view of safety, especially, the railway authority proposes an establishment of the safety case that is the documented demonstration that products comply with the specific safety requirements in railway industry. In case of reliability activities, there is no systematic documented demonstration in the railway industry. At this circumstance, this study presents the establishment of Reliability, Availability and Maintainability Case for railway system based on the MoD(Ministry of Defence) 00-42. This RAM Case will support that systems and products produced from suppliers or manufacturers meet the specific RAM requirements during the system life cycle(i.e, from design to operation & maintenance) through systematic process and evidences. Also, it is expected that railway system operations will be managed and supported from reliability activities in accordance with RAM Case.

• Journal of Applied Reliability
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• v.8 no.1
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• pp.39-59
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• 2008

The performance of weapon system, based on the acceleration of advanced scientific technology, has been reinforced to the state of precision, complexion and multi-function. People have given great interest for a long time on its development, acquisition cost and enormous expense of operation/support. Under this environmental situation, this research paper proposes two kinds of implementation that can improve the RAM(Reliability, Availability, Maintainability) on weapon system. The first section is to understand all of the actual states on its reliability, in the acquisition process and to make the improvement for RAM at the milestones on the acquisition steps. The next section is to establish a defense RAM center, which will be closely cooperated with acquisition organization such as Ministry of Defense, DAPA(Defense Acquisition Program Administration), DTaQ(Defense agency for Technology and Quality) and ADD(Agency for Defense Development), etc. and to conclusively improve the RAM of weapon system in South Korea.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.17-32
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• 1995

The objective of this study is to develop a general design and performance evaluation model for the system designers in the initial design phase of the integrated automatic manufacturing system based on the RAM(Reliability, Availability and Maintainability) and life cycle cost(LCC). The methodology proposed in this research includes the following two stages. First, a deterministic approach to the solution of optimal work station arrangement for the initial system configuration is considered under the assumption that the system availability is one(no failure and maintenance), and then a stochastic simulation model based on RAM and LCC is developed. Using the results of these two stage simulation, a system performance index(SPI) was developed for the performance evaluation of the proposed system. Also a computer program is developed.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.90-93
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• 2013

RAM study has been used for various range of industry such as chemical, electronics, defense industry. Recently, in the offshore & shipbuilding industry, demand of owners to analysis risk has been increased. RAM study is a quantitative pointer to risk based design and provides effective method for improvements. This article shows the result of RAM study for LNG fuel supply system. The result provides information to improve design. This study shows how result of risk assessment affects the design of LNG fuel supply system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.419-427
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• 2020

In the case of large combined weapon systems, such as submarines, the application, and verification of methods of setting the reliability, availability, and maintainability (RAM) target values for conventional weapon systems are limited. Submarines are complex weapon systems with the characteristics of the diversity of operation mode summary and mission profiles (OMS/MP) as well as equipment complexity because they are composed of multiple weapon systems, such as sonar systems and armed systems. Therefore, this study analyzed the development cases of existing weapon systems, i.e., the RAM target value-setting cases, and derived the problems and limitations of the cases to present measures to improve the setting and verification of the ram target values of submarines. In addition, submarines operate around the world and have different operating and maintenance conditions. Therefore, a submarine's ram target values should be set and verified centering on the mission essential equipment and mission critical equipment, instead of all components that constitute weapon systems. This study examined a method to verify the required performance RAM target-value setting, considering the characteristics of submarines as well as the physical performance requirements for the systems and equipment of submarines that must be considered when implementing national defense acquisition projects for submarines.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.220-230
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• 2015

Rolling stock RAMS is a field of engineering which integrates reliability, availability, maintainability and safety (RAMS) characteristics into an inherent product design property through rolling stock system engineering process. It is implemented to achieve operational objectives successfully, and recently the RAMS has become a rapidly growing engineering discipline because it has a great potential to ensure safety and improve cost effectiveness. However, the Korean rolling stock industry has not yet implemented RAMS management in the rolling stock engineering process, despite the issue having been addressed since the introduction of the KTX. Thus, this paper discusses the processes, methods and techniques for RAMS assessment in three parts. Firstly, it outlines a process of the overall RAMS performance assessment for achieving technical RAMS design criteria. Secondly, it discusses a process for assessing the operational RAM and allocating the RAM. This paper also proposes a model for assessing safety-based risk management, which includes five analytic techniques for identifying the causes and consequences of a system failure. Finally, a case example is provided for the risk assessment of the pneumatic braking device.