• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.327-338
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• 2018

Purpose: A risk evaluation procedure is proposed for common failure causes in FMEA(Failure Mode and Effects Analysis). The conventional FMEA does not provide a proper means to compare common failure causes with other failure causes. This research aims to develop a risk evaluation procedure in FMEA where common failure causes and other failure causes exist together. Methods: For each common failure cause, the effect of each combination of its resulting failures is recommended to be reevaluated considering their interactive worsening effect. And the probability that each combination of failures is incurred by the same common cause is also considered. Based on these two factors, the severity of each common cause is determined. Other procedures are similar to the conventional method. Results: The proposed procedure enables to compare and prioritize every failure cause. Thus, the common causes, each of which incurring two or more failures, and other causes, each of which is corresponding to one failure, can be fairly compared. Conclusion: A fair and proper way of comparing the common failure causes and other causes is provided. The procedure is somewhat complicated and requires more works to do. But it is worth to do.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.184-189
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• 2009

In 2008 the total estimated failure costs in the Netherlands was estimated to be 11.4% of the industry's turnover compared to 7.7% seven years earlier. Failure costs can be the consequence of rework as a result of failure to conform to the product requirements and specifications or due to inefficient processes and bad management practices. Many construction companies however are unaware of the exact nature of these costs, their root causes or how to control them. This paper describes work carried out in the Netherlands to identify the different types of failure costs in construction and their root causes. The research described builds on previous findings by another research institution and expands it to include information collected from project cases and a survey of a number of project managers in the construction industry. The paper describes the analysis of the results from cases and the survey to identify the root causes of failure costs. Research shows, for example, that many failure costs are related to the client taking late decisions and making changes to the project requirements.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.387-398
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• 2011

$217Plus^{TM}$, a newly developed as a surrogate of the MIL-HDBK-217, may be widely applied for reliability predictions of electronic systems. In this study, we performed sensitivity study of the $217Plus^{TM}$ system model to various parameters. Specific attention was put to logistics model and its behavior has been examined in terms of non-component failure causes. We first briefly explained the $217Plus^{TM}$ methodology with system level failure rate evaluation. We then applied experimental designs with several failure causes as factors. We used an orthogonal array with three levels of each parameter. Our results indicate that cannot duplicate, induced, and wear-out causes have dominant effects on the system failures and design, parts, and system management have much less but a little strong effects. The results in this study not only figure out the behavior of the predicted failure rate as functions of failure causes but provide meaningful guidelines for practical applications.

• Journal of Engineering Education Research
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• v.13 no.2
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• pp.74-77
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• 2010

This article proposes to examine how the study of failure differs from other technical subjects, and how to turn failure experiences to one's advantage. The authors surveyed the properties of failures in PBL (Project Based Learning) and also examined students' interest and understanding of failure, after introducing failure examples. To investigate how students communicate failure experiences to third parties, reports of the failure experience in PBL were evaluated. From above mentioned surveys, we get the following results. The typical causes of failure in educational institutions are lack of skill in manufacturing and inadequate planning, which conversely are minor causes of failure in the industry. A knowledge database on failure, employed commonly in industry, is not effective in PBL, because projects in educational institutes are usually changed every year. Case studies in failure can be approached from many points of view including causes, processes, effects and safety measures. While teachers should emphasize the notable points in the failure examples in introducing examples of specific topics in machine design, teachers should explain the multiple aspects in the failure examples to educate students about the complexity of actual accidents.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.4
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• pp.609-628
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• 1995

This paper presents a reliability model and a data-analytic procedure for a repairable unit subject to failures due to multiple non-identifiable causes. We regard a failure cause as a state and assume the life distribution for each cause to be exponential. Then we represent the dependency among the causes by a Markov switching model(MSM) and estimate the transition probabilities and failure rates by maximum likelihood(ML) method. The failure data are incomplete due to masked causes of failures. We propose a specific version of EM(expectation and maximization) algorithm for finding maximum likelihood estimator(MLE) under this situation. We also develop statistical procedures for determining the number of significant states and for testing independency between state transitions. Our model requires only the successive failure times of a unit to perform the statistical analysis. It works well even when the causes of failures are fully masked, which overcomes the major deficiency of competing risk models. It does not require the assumption of stationarity or independency which is essential in mixture models. The stationary probabilities of states can be easily calculated from the transition probabilities estimated in our model, so it covers mixture models in general. The results of simulations show the consistency of estimation and accuracy gradually increasing according to the difference of failure rates and the frequency of transitions among the states.

• Proceedings of the Korean Reliability Society Conference
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• 2011.06a
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• pp.257-264
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• 2011

In this study, we performed sensitivity study of the $217Plus^{TM}$ system model to various parameters. Specific attention was put to logistics model and its behavior has been examined in terms of non-component failure causes. We first briefly explained the $217Plus^{TM}$ methodology with system level failure rate evaluation. We then applied experimental designs with several failure causes as factors. We used an orthogonal array with three levels of each parameter. Our results indicate that cannot duplicate, induced, and wear-out causes have dominant effects on the system failures and design, parts, and system management have much less but a little strong effects. The results in this study not only figure out the behavior of the predicted failure rate as functions of failure causes but provide meaningful guidelines for practical applications.

• Journal of the Korean Home Economics Association
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• v.43 no.7 s.209
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• pp.159-170
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• 2005

The purpose of this study was to investigate the causes of managerial failure in small apparel retailers by using the qualitative research method. The study was performed by interviews from thirteen owners/managers who experienced failure as small apparel retailers from November 2003 to February 2004. The causes of failure in the small apparel businesses were human related problems, marketing strategy problems, marketing mix, weak managerial ability, and business environment related problems. Of special interest was causes such as incomplete legal documents with franchisers, unexpected tax investigation from the office of National Tax Administration(NTA), sexual discrimination for women owners, and incapable risk management. It is interesting to note that tax investigation by NTA and sexual discrimination in the business custom were shown as the main causes of business failure in Korea.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.1171-1176
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• 2005

Dispute related to construction projects involving numerous persons is one of the biggest challenges faced by contractors today. It costs a substantial amount of money and time in resolving these kinds of claims. Recently, with the changes in the construction environment and thought of relation with owner, the number of construction claims has increased. But, a majority of these claims do not prevail, and in fact, frequently get dismissed in its entirety. The reasons for such dismissals include the ignorance about the claims, lack of clear and convincing evidence, and so on. But most of reasons are the claims are not managed well on construction process. This paper analyzes the failure causes by relying on past claim failure cases, and then drew works that have connection with failure causes through interview. It also presented importance degree of construction management works.

• Journal of the Korean housing association
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• v.24 no.6
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• pp.151-161
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• 2013

This research is an effort to clarify the causes associated with the 'failure' of public housing projects built in the 20th century. Two of the most brutal symbol of failure were selected: the Pruitt-Igoe built in St. Louis, U.S.A. and the Bijlmermeer in the south of Amsterdam, Netherlands. Many critics have attributed the problems of the selected housing projects to architectural failure, and proposed a series of new approaches to architectural design. The claim that many housing projects 'failed' because they were based on an agenda for social reform, derived from the ideas of the CIAM, presupposes that architects were in the position of authority over providing housing for the poor. This research tries to overturn the belief of architectural community which has placed the responsibility for the failure of public housing on designers. The sense of isolation and powerlessness felt by the residents, and the social problems attendant on those feelings, may be reinforced by design but is not caused by Modern Architecture. It should be stressed that the political-economic and social context is more significant than the architectural design for the failure of public housing projects such as the Pruitt-Igoe and the Bijlmermeer.

• Journal of Korean Society for Quality Management
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• v.44 no.2
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• pp.373-388
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• 2016

Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.