• 한국신뢰성학회지:신뢰성응용연구
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• 제5권3호
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• pp.315-319
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• 2005

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.248-255
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• 2015

Purpose : The purpose of this research is to develop the optimized method and process in the reliability-growth target setting, especially for complex and repairable system (or products) such as vehicle and airplane, construction equipment. Method : A reliability-growth test plan specifies a scenario to achieve the planned reliability value (or reliability target). The major elements in test planning are reliability-growth starting time and reliability level at that time, reliability-growth rate and reliability-growth target. All of them except a reliability target can be referred to the previous development data and reference researches. The reliability target level is directly influencing to test period (or time) which is related to test and warranty cost together. There are a few researches about the reliability target setting method and but showing the limitations to consider the views of engineering, business and customer together. There is no research how to handle the target setting process in detail. Result : We develop the optimized method and systematic process in reliability target setting with considering such views. This research also establish the new concept as production capability which means company (or supplier) capability to product its products. Conclusion : In this research result, we apply the new method to a few projects and can set the reasonable test planning. The developing results is showing the good balance between the developing cost and warranty cost at market.

• 한국정밀공학회지
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• 제23권6호
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• pp.111-118
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• 2006

Recently, the reliability evaluation and analysis are applied far many industrial products which are required to guarantee in quality and efficiency. The purpose of this paper is to present some of reliability evaluation methodologies that are applicable to machine tools. Especially ATC (Automatic Tool Changer), which is a core component of line center, was chosen as the target of the reliability evaluation and analysis. The scope of research is reliability prediction, reliability test and evaluates their results. The results of reliability evaluation have shown the failure rates, MTBF (Mean Time Between Failure), reliability for those components of ATC and real tests reliability through the constructed reliability test-bed. It is expected that proposed methodologies would increase reliability for a high-speed line center.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.133-136
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• 2003

In these days, the reliability analysis and prediction are applied for many industrial products and many products require guaranteeing the quality and efficiency of their products. In this study reliability prediction for core units of machine tools has been performed in order to improve and analyze its reliability. ATC(Automatic Tool Changer) and interface Card of PC-NC that are core component of the machine tools were chosen as the target of the reliability prediction. A reliability analysis tool was used to obtain the reliability data(failure rate database) for reliability prediction. It is expected that the results of reliability prediction be applied to improve and evaluate its reliability. Failure rate, MTBF (Mean Time Between Failure) and reliability for core units of machine tools were evaluated and analyzed in this study.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권3호
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• pp.245-253
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• 2016

Purpose: The purpose of this study is to measure the reliability of complex equipment. Reliability of product is one of the most important factor to achieve competitiveness in the market. While there were many researches for assessing the reliability on components and modules, research on quantitative assessment tool for equipment with many component was little because of equipment's complexity. Methods: In this article, we developed index to assess reliability management system by using IEC 60300 and Reliability Management Tool-kit. With MIR and BARS, we developed reliability index clauses relevant to reliability activities and found weight factor for each clause by survey on experts. Results: The results of this study were as follows; reliability index that can assess both management side and technology side of the company was developed. Conclusion: Using this index, we assessed the reliability of a manufacturing equipment and found out the current reliability level of the manufacturing equipment, and derived improvement points.

• 품질경영학회지
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• 제42권4호
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• pp.633-646
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• 2014

Purpose: The conventional predicted MFTBF by military standard has a wide discrepancy to that of real-world operation, which leads to overstock and increase operation cost. This paper introduces a analyzing frame using operational reliability and cost data to overcome the discrepancy, and provides reliability improvement process employing the analyzing frame. Methods: This paper suggests Reliability-Cost Matrix (R-C Matrix) and Operational Reliability & Cost Index (ORCI) as a tool for reliability evaluation. Results: KOREIP(KAI's Operational Reliability Evaluation and Improvement Process) is developed employing Reliability-Cost Matrix and Operational Reliability & Cost Index. Conclusion: KOREIP provides a process and its activities based on Reliability-Cost Matrix frame. The process and activities leads reliability improvement of aerospace electronic equipments by means of categorizing and follow-up action based on the concept of frame.

• 대한기계학회논문집A
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• 제35권6호
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• pp.629-633
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• 2011

항공기, 철도, 선박과 같은 대형 시스템들은 전기, 기계적으로 매우 복잡한 구조를 가졌으며 부품의 수명만을 고려한 기존의 유지보수에서 탈피하여, 고장분석의 시스템화를 통해 장치의 고유수명과는 관계없이 발생 가능한 우발고장도 대처할 수 있는 신뢰성 기반의 유지보수체계를 연구하여야 한다. 본 연구에서는 선행연구로 필요한 복합 시스템의 신뢰도 계산방법에 관한 연구이다. 복합 시스템의 신뢰도를 효과적으로 계산하기 위해 시스템의 RBD(Reliability Block Diagram)를 구성하고 인접행렬을 사용하여 RBD(Reliability Block Diagram)를 행렬로 표현한다. 또한 RBD(Reliability Block Diagram)행렬을 통하여 신뢰도 경로행렬과 고장열거 행렬을 구성하여 시스템의 신뢰도를 계산한다. 본 연구에서 제안한 알고리즘은 자동화, 시스템화가 가능하며 현재 개발하고 있는 신뢰도 정보관리 시스템 및 신뢰성 기반 유지보수 시스템에서 활용될 것이다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1914-1917
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• 2005

Recently, the reliability evaluation and analysis are applied for many industrial products, and many products are required to guarantee in quality and in efficiency. The purpose of this paper is to present some of reliability evaluation methodologies that are applicable to machine tools. Especially ATC(Automatic Too Changer), which is core component of line center, was chosen as the target of the reliability evaluation and analysis. The scope of research is reliability prediction, reliability test and evaluates their results. The results of this research has shown the failure rate, MTBF(Mean Time Between Failure), reliability for those components and real tests reliability through constructed reliability test-bed. It is expected that proposed methodologies will increase reliability for high speed line center.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권1호
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• pp.59-69
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• 2009

LEDs have rapidly replaced old light devices such as incandescent or fluorescent lamps, and have been widely applied in general lighting, signals, automobile, signs and others. Since LEDs are for both indoor and outdoor use, temperature and humidity inevitably affect its reliability. We explain the result of the degradation life test on LEDs, and guide to reliability analysis procedure. Analysis on reliability measures are performed by Weibull++6 program, and a common shape parameter of Weibull distribution on the LED is suggested. Also, we make a description of reliability analysis procedures for the degradation data using collected test data from degradation tests. Reliability analysis procedures are consisted of estimating degradation models and failure time, verifying of distribution and parameters of the distribution, and estimating of reliability measures. Finally, this paper suggests reliability analysis method for light characteristics on LEDs.

• 대한안전경영과학회지
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• 제10권3호
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• pp.81-87
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• 2008

The reliability prediction and evaluation for general electronic components are required to guarantee in quality and in efficiency. Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. In this study reliability prediction of electronic components, that is the interface card, which is used in the CNC(Computerized Numerical Controller) of machine tools, was carried out using PRISM reliability prediction specification. Reliability performances such as MTBF(Mean Time Between Failure), failure rate and reliability were obtained, and the variation of failure rate for electronic components according to temperature change was predicted. The results obtained from this study are useful information to consider a counter plan for weak components before they are used.