• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.485-491
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• 2019

In this paper, we present a process and case of RAM analysis using Field-Data of the ground weapon system in operation in the army. In order to perform RAM analysis in filed-Data, we propose data collection, data refining and calibration, and RAM analysis process. RAM analysis was performed with the RAM verification and evaluation system developed by Defense Agency for Technology and Quality. We enhance the objectivity and reliability in result of data, which contains a variety of conditions; operation and maintenance concept of domestic ground weapon system, relevant regulation and after-sales service data of developer. Results are compared 2015, 2018 and development RAM value. We prove results of RAM analysis through discussion experts. Studies show that proposed method can effectively apply database from setting to evaluation RAM value in various ground weapon system.

• Journal of the Korean Society of Systems Engineering
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• v.14 no.1
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• pp.44-51
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• 2018

The purpose of RAM analysis in weapon systems is to reduce life cycle costs, along with improving combat readiness by meeting RAM target value. We analyzed the sensitivity of the RAM analysis parameters to the use of the operating system by using the Markov Process based model (MPS, Markov Process Simulation) developed for RAM analysis. A Markov process-based RAM analysis model was developed to analyze the sensitivity of parameters (MTBF, MTTR and ALDT) to the utility of the 81mm mortar. The time required for the application to reach the steady state is about 15,000H, which is about 2 years, and the sensitivity of the parameter is highest for ALDT. In order to improve combat readiness, there is a need for continuous improvement in ALDT.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1985.10a
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• pp.3.2-6
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• 1985

There are two major fields for system effectiveness investogations-RAM analysis and performance(capacity) analysis. The investgation methods for system effectiveness are discussed. And two prototypes are presented for RAM analysis and performance analysis.

• Journal of Applied Reliability
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• v.17 no.3
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• pp.264-271
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• 2017

Purpose: Field operation data contains missing values or outliers due to various causes of the data collection process, so caution is required when utilizing RAM analysis results by field operation data. The purpose of this study is to present a method to minimize the RAM analysis error of the field data to improve the accuracy. Methods: Statistical methods are presented for processing of the outliers and the missing values of the field operating data, and after analyzing the RAM, the differences between before and after applying the technique are discussed. Results: The availability is estimated to be lower by 6.8 to 23.5% than that before processing, and it is judged that the processing of the missing values and outliers greatly affect the RAM analysis result. Conclusion: RAM analysis of OO weapon system was performed and suggestions for improvement of RAM analysis were presented through comparison with the new and current method. Data analysis results without appropriate treatment of error values may result in incorrect conclusions leading to inappropriate decisions and actions.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.1
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• pp.41-49
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• 2015

Analysis and test of hydrodynamic ram in welded metallic tanks containing water were performed to investigate the phenomena and to understand the effects on the resulting structural behavior. Arbitrary Lagrange-Euler coupling method was used for the analysis of the fluid-structure interaction occurring in the hydrodynamic ram, where the projectile, tank, and water are exchanging load, momentum, and energy during the traveling of the projectile through the water of the tank. For a better representation of the physical phenomena, modeling of the welded edges is added to the analysis to simulate the earlier weld line fracture and its influence on the resulting hydrodynamic ram behavior. Corresponding hydrodynamic tests were performed in a modified gas gun facility, and the following panel-based examinations of various parameters, such as displacement, velocity, stress, and energy, as well as hydrodynamic ram pressure show that the analysis and test are well correlated, and thus the results of the study reasonably explain the characteristics of the hydrodynamic ram. The methodology and procedures of the present study are applicable to the hydrodynamic ram assessment of airframe survivability design concepts.

• 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.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.395-412
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• 2012

RAM analysis using field data is important and useful for acquisition and operation of weapon systems. But this kind of analysis didn't conducted due to the absence of weapon system's failure data in case of warship. This study suggest failure tracking process based on maintenance and repair parts consumption data and proves suggested method enables conducting RAM analysis. This method obtains validity through field operator's reviews. The results on 9 warships in this study significantly correspond with weapon system operator's experiences. Because the result of this study contains effects of various operational environments in field, it will useful for correction and verification on existing another weapon system's RAM estimates. If this kind of RAM data are sufficiently accumulated, it will be used to DB of korean unique RAM analysis.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.714-721
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• 2018

This study proposes a risk evaluation method based on RAM and AHP data in order to prevent subjectivity of risk assessment. The risk assessment consist of Risk Likelihood(RL) and Risk Consequence(RC) in five levels. However, risk analysis of warships is hard to make a judgment because of small quantity production(Ship), long building period, equipment changes, complexity, various kinds of equipments, etc. The proposed RAM data and AHP analysis method are used to quantify each level quantitatively. RAM(MTBF) date is used to classify the RL, and AHP analysis is used to classify the RC. These scientific and data-based method will increase objectivity as well as efficiency of risk evaluation.

• Convergence Security Journal
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• v.19 no.2
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• pp.163-174
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• 2019

RAM analysis determines the range of resources to be invested by presenting the development goals of the weapon system. If the RAM analysis is not performed properly, it can cause a huge increase in business costs. While the cumulative cost ratio in the concept study is less than 1% of the total cost, 65-70% of the total lifecycle cost is determined and can't be reduced later. Therefore, RAM analysis is crucial in precedent study. When calculating the target RAM value by writing an existing OMS/MP, new functions and the future missions are hardly considered and reflected. Therefore, this paper proposes a method to establish OMS/MP by deriving arguments based on Delphi and Bayesian theory focusing on unmanned combat vehicle.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.855-866
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• 2023

With the rapid advancement and sophistication of defense weapon systems, the government, military, and the defense industry have conducted various innovative attempts to improve the efficiency of post-logistics support(PLS). The Ministry of Defense has mandated RAM-C(Reliability, Availability, and Maintainability-Cost) analysis as a requirement according to revised Total Life Cycle System Management Code of Practice in May 2022. Especially, for the project budget forecast of new PBL(Performance Based Logistics) business contacts, RAM-C is recognized as an obligatory factor. However, relevant entities have not officially provided guidelines or manuals for RAM-C analysis, and each defense contractor conducts RAM-C analysis with different standards and methods to win PBL-related business contract. Hence, this study aims to contribute to the generalization of the analysis procedure by presenting a cost analysis case based on RAM-C for the supply of military depot maintenance PBL project. This study presents formulas and procedures to determine requirements of military depot maintenance PBL project for repair parts supply. Moreover, a sensitivity analysis was conducted to find the optimal cost/utilization ratio. During the process, a correlation was found between supply delay and total cost of ownership as well as between cost variability and utilization rate. The analysis results are expected to provide an important basis for the conceptualization of the cost analysis for the supply of military depot maintenance PBL project and are capable of proposing the optimal utilization rate in relation to cost.