효과적인 공정 FMEA 실행 방법

안동근(Dong Geun Ahn),최정희(Jung Hee Choi),장중순(Joong Soon Jang) 한국신뢰성학회 2021 신뢰성응용연구 Vol.21 No.2

Purpose: This paper proposes the methods and procedures to effectively identify and select potential failure modes to perform a process failure modes and effects analysis (FMEA). Methods: Detailed analyses of processes are generally required to prevent possible omissions and improper utilization of potential failure modes. In this study, a process decomposition is proposed for all procedures summarized in the process-flow chart to identify potential failure modes. To provide detailed identifications of the potential failure modes, a method of decomposing the process into work units is described. In addition, the 4M+1E elements, which are required for the decomposition, are found and listed. Each of the operational performance elements determined in this step was found to interfere with the work. Further, a method of identifying potential failure modes is proposed based on the determined work obstructions. Results: The process flow for an example screw-tightening procedure was decomposed into work units based on its process FMEA. A method to predict the potential failure modes for each disassembled work unit was also established based on the obstacles to work performance. Conclusion: By applying the proposed method to a screw-fastening process, it was confirmed that a process FMEA performed without process decomposition found unexpected potential failure modes.

The time varying reliability analysis for space focusing mechanism based on probability model

Penghui Cheng,Mengyuan Wu,Chuang Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

Compared with the ground focusing mechanism, the working environment of space focusing mechanism is more harsh and complicated. Hence the accurate prediction of its reliability is indispensable. However, it is unrealistic to obtain sample parameters of reliability analysis through repeated entity tests, due to the limitation of project cost and timetable, which lead to many existing model cannot be applied directly. We focus on a screw guide type space focusing mechanism, and propose a new time varying reliability probabilistic model that can characterize the reliability of discontinuous motion mechanisms with discrete multi-load. Its primary uncertainties and failure modes are evaluated quantitatively by failure mode effects analysis. The total damage of intermittent operation is treated as accumulative effect caused by each focusing work. And main parameters of the model are obtained by analytical calculation of mechanism wear reliability model. Finally, an integrated theoretical method are constructed and verified in this article, and the time varying reliability of proposed focusing mechanism are also discussed.

6 시그마 프로세스를 이용한 소형 직류 모터의 소음 절감

차원준,최연선 한국소음진동공학회 2003 한국소음진동공학회 논문집 Vol.13 No.7

This paper studies on the noise reduction for a small automobile DC Motor (a window motor) using the 6 sigma process. The application of 6 sigma process suggested reliable and valuable statistical data for the quality of the DC motor at the production line. In the measurement step in 6 sigma process. the FMEA(failure mode effect analysis) were used for the detection of noise sources. The application of 6 sigma Process gave not only the improving method for the quality of the DC motor but also the confidence of improvement Itself since it was done on the basis of the test results for a number of DC motors at the production line. Consequently the 6 sigma process was proved very effective for the noise reduction at the production line.

Knowledge-enriched Process FMEA Model for Process Planning

Zheng, Lian-yu,Chin, Kwai-sang,Wei, Li 한국품질경영학회 2002 The Asian Journal on Quality Vol.3 No.1

Most process FMEA systems in the market simply fill out the worksheet/form, and can not effectively express, organize, and utilize process failure knowledge of production process during process planning. This paper proposes a knowledge-enriched representation model for enhancing process FMEA in process planning. This model can effectively represent the process FMEA knowledge other than specific process failure instances or data. Furthermore, in order to effectively utilize the previous process FMEA knowledge, an algorithm is proposed to calculate the similarity among process failure problems based on “concept distance”. A knowledge-enriched process FMEA tool has been developed by adopting Web technique so as to provide cooperative process FMEA services for process planner on the Internet or Intranet.

Research on Increasing the Production Yield Rate by Six Sigma Method : A Case of SMT Process of Main Board

Lin, Ching-Kun,Chen, Hsien-Ching,Li, Rong-Kwei,Chen, Ching-Piao,Tsai, Chih-Hung The Korean Society for Quality Management 2009 The Asian Journal on Quality Vol.10 No.1

Face the process yield rate improvements of motherboard, although general enterprises finish deployment goal of each functions by overall quality managements, through quality improvement methods, industry engineering methods, plan-do-check-act (PDCA) methods and other improvement solutions, but it is only can be improved partially and unable to enhance the yield rate of product to the target. It only can takes one step ahead to enhance the process yield rate of motherboard with six sigma ($6{\sigma}$) overall DMAIC process and tactics. This research aimed to use six sigma quality improvement tactics by DMAIC systematic procedure and tactics, and find the key factors that effect to the process yield rate of surface mount technology. It also identified the keys input and process and output index to satisfy customer requirements and internal process index. The results showed that the major effective factors by fishbone and process failure modes and effects analysis (PFMEA). If the index of input and output that can be quantified, the optimum parameter can be found through design of experiment to ensure that the process is stable. If the factor of input and output that cannot be quantified, we found out the effective countermeasure by Mind_Mapping, make sure whole processes can be controlled stably, to reach the high product quality and enhance the customer satisfaction.

Study of Failure Mode and Effect Analysis in Brachytherapy

Soon Sung Lee(이순성),Dong Wook Park(박동욱),Dong Oh Shin(신동오),Dong Wook Kim(김동욱),Kum Bae Kim(김금배),Yoon-Jin Oh(오윤진),Juhye Kim(김주혜),Na Hye Kwon(권나혜),Kyeong Min Kim(김경민),Sang Hyoun Choi(최상현) 한국방사선학회 2017 한국방사선학회 논문지 Vol.11 No.7

근접방사선치료는 일반적으로 외부방사선치료와 병행하여 수행되고 치료단계가 매우 복잡하며 이로 인해 방사선 사고가 발생될 수 있다. 본 연구에서는 이를 해결하기 위해 근접방사선치료에 사고유형과 영향 분석(Failure mode and effects analysis, FMEA) 방법을 적용하여 프로세스 맵을 구성하고 이를 기반으로 각 치료단계에 대한 위해도를 산출하였다. 프로세스 맵은 “외래 및 진료”와 “근접방사선 모의치료”, “CT 모의 치료”, “근접방사선치료계획”, “방사선치료”로 총 5단계로 구성하였으며, 각 치료단계를 세분화하여 세부단계를 작성하였다. 위해도를 산출하기 위해 의사와 의학물리사, 선량설계사, 방사선사, 간호사가 참여하여 세부단계마다 발생빈도와 심각도, 불검출도를 평가하였다. 전반적으로 프로세스 맵은 각 치료단계마다 환자 신원 확인 절차가 우선적으로 수행되며, 이는 다른 환자로 오인하여 서로 다른 치료계획이 수립되어 방사선사고가 발생될 우려가 있다. 프로세스 맵을 기반으로 작성한 세부단계에 대해 위해도를 평가한 결과, 전반적으로 “외래 및 진료”와 “근접방사선치료계획” 과정이 높은 위해도로 평가되었다. 직종마다 평가한 위해도는 서로 다른 경향을 보였으며, 간호사는 방사선치료를 제외한 모든 과정이 55점 이상의 위해도를 보였으며, “근접방사선 모의치료” 과정이 88.8점으로 가장 높았다. 방사선치료를 수행하는 의료기관마다 치 료단계가 다소 차이가 있으므로 해당 기관에 대한 프로세스 맵을 작성하고 위해도를 산출하여 중점관리 항목을 집중적으로 리스크 관리가 수행되어야 할 것으로 생각된다. Brachytherapy is generally performed in conjunction with external radiation therapy, and the treatment course is very complicated, which can lead to radiation accidents. In order to solve this problem, we designed the process map by applying the failure mode and effects analysis (FMEA) method to the Brachytherapy and scored the risk priority number (RPN) for each treatment course based on this process map. The process map consisted of five steps, Patient consulting , “Brachytherapy simulation , CT simulation , Brachytherapy treatment planning and Treatment . In order to calculate the RPN, doctor, medical physicist, dose planners, therapist, and nurse participated in the study and evaluated occurrence, severity, and lack of detectability at each detail step. Overall, the process map is preceded by a patient identification procedure at each treatment stage, which can be mistaken for another patient, and a different treatment plan may be established to cause a radiation accident. As a result of evaluating the RPN for the detailed steps based on the process map, overall Patient consulting and Brachytherapy treatment planning step were evaluated as high risk. The nurses showed a tendency to be different from each other, and the nurses had a risk of 55 points or more for all the procedures except Treatment , and the Brachytherapy simulation step was the highest with 88.8 points. Since the treatment stage differs somewhat for each medical institution performing radiotherapy, it is thought that the risk management should be performed intensively by preparing the process map for each institution and calculating the risk RPN.

현실적 공정 FMEA 평가기준 개발

김태혁(T. H. Kim),장중순(Joong Soon Jang),이은열(E. Y. Lee) 한국신뢰성학회 2010 신뢰성응용연구 Vol.10 No.2

Failure mode and effects analysis (FMEA) is a widely used technique to assess or to improve reliability of products or processes at early stage of development. Traditionally, the prioritization of failures for corrective actions is performed by evaluating risk priority numbers (RPN). In practice, due to insufficient evaluation criteria specific to related products and processes, RPN is not always evaluated properly. This paper reestablishes an effective methodology for prioritization of failure modes in FMEA procedure. Revised evaluation criteria of RPN are devised and a refined FMEA sheet is introduced. To verify the proposed methodology, it is applied to inspection processes of PCB products.

근접방사선치료에 관한 사고유형과 영향분석 연구

이순성,박동욱,신동오,김동욱,김금배,오윤진,김주혜,권나혜,김경민,최상현 한국방사선학회 2017 한국방사선학회 논문지 Vol.11 No.7

근접방사선치료는 일반적으로 외부방사선치료와 병행하여 수행되고 치료단계가 매우 복잡하며 이로 인해 방사선 사고가 발생될 수 있다. 본 연구에서는 이를 해결하기 위해 근접방사선치료에 사고유형과 영향분석(Failure mode and effects analysis, FMEA) 방법을 적용하여 프로세스 맵을 구성하고 이를 기반으로 각 치료단계에 대한 위해도를 산출하였다. 프로세스 맵은 “외래 및 진료”와 “근접방사선 모의치료”, “CT 모의치료”, “근접방사선치료계획”, “방사선치료”로 총 5단계로 구성하였으며, 각 치료단계를 세분화하여 세부단계를 작성하였다. 위해도를 산출하기 위해 의사와 의학물리사, 선량설계사, 방사선사, 간호사가 참여하여 세부단계마다 발생빈도와 심각도, 불검출도를 평가하였다. 전반적으로 프로세스 맵은 각 치료단계마다 환자 신원 확인 절차가 우선적으로 수행되며, 이는 다른 환자로 오인하여 서로 다른 치료계획이 수립되어 방사선사고가 발생될 우려가 있다. 프로세스 맵을 기반으로 작성한 세부단계에 대해 위해도를 평가한 결과, 전반적으로 “외래 및 진료”와 “근접방사선치료계획” 과정이 높은 위해도로 평가되었다. 직종마다 평가한 위해도는 서로 다른 경향을 보였으며, 간호사는 방사선치료를 제외한 모든 과정이 55점 이상의 위해도를 보였으며, “근접방사선 모의치료” 과정이 88.8점으로 가장 높았다. 방사선치료를 수행하는 의료기관마다 치료단계가 다소 차이가 있으므로 해당 기관에 대한 프로세스 맵을 작성하고 위해도를 산출하여 중점관리 항목을 집중적으로 리스크 관리가 수행되어야 할 것으로 생각된다. Brachytherapy is generally performed in conjunction with external radiation therapy, and the treatment course is very complicated, which can lead to radiation accidents. In order to solve this problem, we designed the process map by applying the failure mode and effects analysis (FMEA) method to the Brachytherapy and scored the risk priority number (RPN) for each treatment course based on this process map. The process map consisted of five steps, Patient consulting", “Brachytherapy simulation", "CT simulation", "Brachytherapy treatment planning" and "Treatment". In order to calculate the RPN, doctor, medical physicist, dose planners, therapist, and nurse participated in the study and evaluated occurrence, severity, and lack of detectability at each detail step. Overall, the process map is preceded by a patient identification procedure at each treatment stage, which can be mistaken for another patient, and a different treatment plan may be established to cause a radiation accident. As a result of evaluating the RPN for the detailed steps based on the process map, overall "Patient consulting" and "Brachytherapy treatment planning" step were evaluated as high risk. The nurses showed a tendency to be different from each other, and the nurses had a risk of 55 points or more for all the procedures except "Treatment", and the "Brachytherapy simulation" step was the highest with 88.8 points. Since the treatment stage differs somewhat for each medical institution performing radiotherapy, it is thought that the risk management should be performed intensively by preparing the process map for each institution and calculating the risk RPN.

엔지니어링 프로세스 관리를 위한 기술품질정보 관리 시스템 개발

정홍진(HongJinJeong),남성호(SungHoNam),백재용(JaeYongBaek),최영재(YoungJaeChoi),김보현(BoHyunKim) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

본 논문은 엔지니어링 프로세스에서 발생하는 기술·품질정보를 수집하고 이를 체계적으로 관리하기 위하여 고장나무분석(FTA: fault tree analysis) 와 잠재적 고장형태 및 영향분석(FMEA: Failure mode & effect analysis)의 관계 분석을 통해 지식기반 기술·품질정보 관리 시스템을 제안한다. 지식기반 기술·품질정보 관리시스템은 프로젝트 관리 기법인 작업분류체계(WBS: work breakdown structure) 를 바탕으로 하여 다섯 가지 유형별 엔지니어링 업무를 정의한다. 그리고 엔지니어링 업무를 수행함으로써 수집되는 기술·품질정보는 FTA 로 구성된다. 이는 FMEA 로 변환하여 잠재적인 품질이슈 분석이 가능하도록 시스템을 구현한다.

AHP 방법론을 적용한 FMEA 치명도 평가 사례연구

김태희 한국기계기술학회 2020 한국기계기술학회지 Vol.22 No.4

Failure mode and effects analysis(FMEA) is popular approach applied to examine potential failures in equipment designs and maintenance of equipments. Risk Priority Number(RPN) is used as an index for the criticality of fault modes in FMEA and RCM(reliability centered maintenance). Traditional RPN approach does not have much credit as a index for the criticality because it does not reflect their experience and the governing logic is apart from their knowledge. Multiple Criteria Decision Method(MCDM) is a proven approach applied to evaluate multiple conflicting criteria in decision making. MCDM can be applied as a tool for RPN evaluation. This study was carried out to investigate application of Analytical Hierarchy Process(AHP) in evaluating RPN.