• Title/Summary/Keyword: failure evaluation

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Differential Effects of Recovery Efforts on Products Attitudes (제품태도에 대한 회복노력의 차별적 효과)

  • Kim, Cheon-GIl;Choi, Jung-Mi
    • Journal of Global Scholars of Marketing Science
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    • v.18 no.1
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    • pp.33-58
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    • 2008
  • Previous research has presupposed that the evaluation of consumer who received any recovery after experiencing product failure should be better than the evaluation of consumer who did not receive any recovery. The major purposes of this article are to examine impacts of product defect failures rather than service failures, and to explore effects of recovery on postrecovery product attitudes. First, this article deals with the occurrence of severe and unsevere failure and corresponding service recovery toward tangible products rather than intangible services. Contrary to intangible services, purchase and usage are separable for tangible products. This difference makes it clear that executing an recovery strategy toward tangible products is not plausible right after consumers find out product failures. The consumers may think about backgrounds and causes for the unpleasant events during the time gap between product failure and recovery. The deliberation may dilutes positive effects of recovery efforts. The recovery strategies which are provided to consumers experiencing product failures can be classified into three types. A recovery strategy can be implemented to provide consumers with a new product replacing the old defective product, a complimentary product for free, a discount at the time of the failure incident, or a coupon that can be used on the next visit. This strategy is defined as "a rewarding effort." Meanwhile a product failure may arise in exchange for its benefit. Then the product provider can suggest a detail explanation that the defect is hard to escape since it relates highly to the specific advantage to the product. The strategy may be called as "a strengthening effort." Another possible strategy is to recover negative attitude toward own brand by giving prominence to the disadvantages of a competing brand rather than the advantages of its own brand. The strategy is reflected as "a weakening effort." This paper emphasizes that, in order to confirm its effectiveness, a recovery strategy should be compared to being nothing done in response to the product failure. So the three types of recovery efforts is discussed in comparison to the situation involving no recovery effort. The strengthening strategy is to claim high relatedness of the product failure with another advantage, and expects the two-sidedness to ease consumers' complaints. The weakening strategy is to emphasize non-aversiveness of product failure, even if consumers choose another competitive brand. The two strategies can be effective in restoring to the original state, by providing plausible motives to accept the condition of product failure or by informing consumers of non-responsibility in the failure case. However the two may be less effective strategies than the rewarding strategy, since it tries to take care of the rehabilitation needs of consumers. Especially, the relative effect between the strengthening effort and the weakening effort may differ in terms of the severity of the product failure. A consumer who realizes a highly severe failure is likely to attach importance to the property which caused the failure. This implies that the strengthening effort would be less effective under the condition of high product severity. Meanwhile, the failing property is not diagnostic information in the condition of low failure severity. Consumers would not pay attention to non-diagnostic information, and with which they are not likely to change their attitudes. This implies that the strengthening effort would be more effective under the condition of low product severity. A 2 (product failure severity: high or low) X 4 (recovery strategies: rewarding, strengthening, weakening, or doing nothing) between-subjects design was employed. The particular levels of product failure severity and the types of recovery strategies were determined after a series of expert interviews. The dependent variable was product attitude after the recovery effort was provided. Subjects were 284 consumers who had an experience of cosmetics. Subjects were first given a product failure scenario and were asked to rate the comprehensibility of the failure scenario, the probability of raising complaints against the failure, and the subjective severity of the failure. After a recovery scenario was presented, its comprehensibility and overall evaluation were measured. The subjects assigned to the condition of no recovery effort were exposed to a short news article on the cosmetic industry. Next, subjects answered filler questions: 42 items of the need for cognitive closure and 16 items of need-to-evaluate. In the succeeding page a subject's product attitude was measured on an five-item, six-point scale, and a subject's repurchase intention on an three-item, six-point scale. After demographic variables of age and sex were asked, ten items of the subject's objective knowledge was checked. The results showed that the subjects formed more favorable evaluations after receiving rewarding efforts than after receiving either strengthening or weakening efforts. This is consistent with Hoffman, Kelley, and Rotalsky (1995) in that a tangible service recovery could be more effective that intangible efforts. Strengthening and weakening efforts also were effective compared to no recovery effort. So we found that generally any recovery increased products attitudes. The results hint us that a recovery strategy such as strengthening or weakening efforts, although it does not contain a specific reward, may have an effect on consumers experiencing severe unsatisfaction and strong complaint. Meanwhile, strengthening and weakening efforts were not expected to increase product attitudes under the condition of low severity of product failure. We can conclude that only a physical recovery effort may be recognized favorably as a firm's willingness to recover its fault by consumers experiencing low involvements. Results of the present experiment are explained in terms of the attribution theory. This article has a limitation that it utilized fictitious scenarios. Future research deserves to test a realistic effect of recovery for actual consumers. Recovery involves a direct, firsthand experience of ex-users. Recovery does not apply to non-users. The experience of receiving recovery efforts can be relatively more salient and accessible for the ex-users than for non-users. A recovery effort might be more likely to improve product attitude for the ex-users than for non-users. Also the present experiment did not include consumers who did not have an experience of the products and who did not perceive the occurrence of product failure. For the non-users and the ignorant consumers, the recovery efforts might lead to decreased product attitude and purchase intention. This is because the recovery trials may give an opportunity for them to notice the product failure.

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Evaluation on the Reliability Attributes of Finite Failure NHPP Software Reliability Model Based on Pareto and Erlang Lifetime Distribution (파레토 및 어랑 수명분포에 근거한 유한고장 NHPP 소프트웨어 신뢰성모형의 신뢰도 속성에 관한 평가)

  • Min, Kyung-il
    • Journal of Industrial Convergence
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    • v.18 no.3
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    • pp.19-25
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    • 2020
  • In the software development process, software reliability evaluation is a very important issue. In particular, finding the optimal development model that satisfies high reliability is the more important task for software developers. For this, in this study, Pareto and Erlang life distributions were applied to the finite failure NHPP model to evaluate the reliability attributes. For this purpose, parametric estimation is applied to the maximum likelihood estimation method, and nonlinear equations are calculated using the bisection method. As a result, the Erlang model showed better performance than the Pareto model in the evaluation of the strength function and the mean value function. Also, as a result of inputting future mission time and evaluating reliability, the Erlang model showed an effectively high trend together with the Pareto model, while the Goel-Okumoto basic model showed a decreasing trend. In conclusion, the Erlang model is the best model among the proposed models. Through this study, it is expected that software developers will be able to use it as a basic guideline for exploring and evaluating the optimal software reliability model.

Effect of Evaluation Response Spectrum on the Seismic Risk of Structure (평가용 스펙트럼이 구조물의 지진리스크에 미치는 영향)

  • Kim, Min-Kyu;Choi, In-Ki
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.6
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    • pp.39-46
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    • 2009
  • The selection of an evaluation response spectrum can have a significant effect on the seismic fragility evaluation of a structure. A method for modifying the seismic fragility parameters that are calculated based on the design spectrum is described in this study. The modification factor is used to modify the original fragility parameters. The HCLPF (High Confidence of Low Probability of Failure) acceleration levels of the electric system using previous design spectrum and uniform hazard spectrum (UHS) were compared. Finally, seismic risk analyses were performed according to a uniform hazard spectrum. From the results, it was concluded that based on the design spectrum, seismic risk for the electric system might be underestimated.

SYSTEM RELIABILITY-BASED EVALUATION OF BRIDGE SYSTEM REDUNDANCY AND STRENGTH (체계신뢰성에 기초한 교량의 시스템여용성 및 저항강도 평가)

  • 조효남;이승재;임종권
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.240-247
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    • 1993
  • The precise prediction of reserved carrying capacity of bridge as a system is extremely difficult especially when the bridges are highly redundant and significantly deteriorated or damaged. This paper is intended to propose a new approach for the evaluation of reserved system carrying capacity of bridges in terms of equivalent system-strength, which may be defined as a bridge system-strength corresponding to the system reliability of the bridge. This can be derived from an inverse process based on the concept of FOSM form of system reliability index. It may be emphasized that this approach is very useful for the evaluation of the deterministic system redundancy and reserve strength which are measured in terms of either probabilistic system redundancy factor and reserve factor or deterministic system redundancy factor and reserve factor. The system reliability of bridges is formulated as a parallel-series model obtained from the FAM(Failure Mode Approach) based on the major failure mechanisms. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed approach and method for the system redundancy and reserve safety/strength are applied to the safety assessment of actual RC and steel box-girder bridges. The results of the evaluation of reserved system safety or bridge system-strength in terms of the system redundancy and the system safety/strength are significantly different from those of element reliability-based or conventional methods.

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The Optimization Study on the Test Method of Remanufactured Power Steering Oil Pump by Using FMEA (FMEA를 활용한 재제조 파워스티어링 오일펌프 시험법에 대한 최적화 연구)

  • Seo, Youngkyo;Jung, Dohyun;Yu, Sangseok;Rha, Wanyong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.24 no.1
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    • pp.90-98
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    • 2016
  • Currently government certified test method for an automobile remanufactured products is insufficient. Thus many automotive parts in the remanufacturing market are lacking proper evaluation criteria and production of defective products are causing customer dissatisfaction. In this paper a power steering oil pump, which requires stringent manufacturing standards, is studied by the failure mode and effect analysis approach. The research suggested that the test criteria such as discharge flow characteristic test, tightness test, pulley run-out test, pressure switch operation test, low temperature test and rotation pressure durability test should be performed to evaluate the reliability of remanufactured power steering oil pumps. As a result of tests, the performance of remanufactured power steering oil pump satisfied the evaluation criteria of pressure switch operation test and low temperature test. However, the remanufactured power steering oil pump failed to satisfy the evaluation criteria on discharge performance test, tightness test and pulley run-out test. These performance evaluation tests proved the necessity of standard process for the remanufactured power steering oil pump.

Seismic Performance Evaluation Methodology for Nuclear Power Plants (원전 구조물의 내진성능 평가 방법론 고찰)

  • Ann, Hojune;Kim, Yousok;Kong, Jung Sik;Choi, Youngjin;Choi, Se Woon;Lee, Min Seok
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.14 no.2
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    • pp.32-40
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    • 2018
  • Since 2000, the frequency of earthquakes beyond the 5.0 magnitude quake has been increasing in the Korean peninsula. For instance, the 5.0-magnitude earthquake in Baekryong-do in 2003 has occurred, and recent earthquake with Gyeongju(2016) and Pohang(2017) measured respectively magnitude of 5.2 and 5.8 on the Richter scale. As results, the public concern and anxiety about earthquakes are increasing, and therefore it is necessarily required for social infrastructure to reinforce seismic design and energy production facilities directly related to the national economy and security. This study represents the analysis of seismic performance evaluation methodology such as Seismic Margin Assessment (SMA), Seismic Probabilistic Risk Assessment (SPRA), High Confidence Low Probability Failure (HCLPF) in nuclear power plants in order to develop optimal seismic performance improvement. Current methodologies to evaluate nuclear power plants are also addressed. Through review of the nuclear structure evaluation past and current trend, it contributes to be the basis for the improvement of evaluation techniques on the next generation of nuclear power plants.

Dynamic Response based System Reliability Analysis of Structure with Passive Damper - Part 2: Assessment of System Failure Probability (수동형 댐퍼를 장착한 구조물의 동적응답기반 신뢰성 해석 - 제2편: 시스템 파괴확률 산정)

  • Kim, Seung-Min;Ok, Seung-Yong
    • Journal of the Korean Society of Safety
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    • v.31 no.5
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    • pp.95-101
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    • 2016
  • This study proposes a multi-scale dynamic system reliability analysis of control system as a method of quantitative evaluation of its performance in probabilistic terms. In this second paper, we discuss the control effect of the viscous damper on the seismic performance of the structure-level failure. Since the failure of one structural member does not necessarily cause the collapse of the structural system, we need to consider a set of failure scenarios of the structural system and compute the sum of the failure probabilities of the failure scenarios where the statistical dependence between the failure scenarios should be taken into account. Therefore, this computation requires additional system reliability analysis. As a result, the proposed approach takes a hierarchial framework where the failure probability of a structural member is computed using a lower-scale system reliability with the union set of time-sequential member failures and their statistical dependence, and the failure probability of the structural system is again computed using a higher-scale system reliability with the member failure probabilities obtained by the lower-scale system reliability and their statistical dependence. Numerical results demonstrate that the proposed approach can provide an accurate and stable reliability assessment of the control performance of the viscous damper system on the system failure. Also, the parametric study of damper capacity on the seismic performance has been performed to demonstrate the applicability of the proposed approach through the probabilistic assessment of the seismic performance improvement of the damper system.

Various Perspectives on the Concept of Failure and its Implication in Engineering Education (실패에 관한 다양한 관점과 공학교육에서의 함의)

  • Han, Kyonghee;Yun, Ilgu;Lee, Kangtaek;Kim, Taeyeon
    • Journal of Engineering Education Research
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    • v.17 no.6
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    • pp.12-19
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    • 2014
  • Failure is an important part of engineering practice. Engineers utilize all of their competences and resources in order for their products or processes to meet the initial intention and purpose, and not to fail. However, the technological products sometimes end up with failure. The failure, in many cases, is related to non-technological factors or systems, not just limited to technological factors. Moreover, the evaluation of failure is performed by a variety of agents, including consumers, civic groups, government as well as professional groups. Thus, this study raises an issue that the existing concept of failure, which focuses on the operation of function, is not sufficient enough to properly cover the success or failure of technology required by the modern society. In the recent trends of engineering, new concepts and methods have been developed by expanding the traditional concept or introducing a new perspective of failure, so that engineering failure can be better understood in the mutual relationship between technology and society. This research attempts to suggest a methodology of how the failure of engineering can be utilized and properly combined in the major education, design education and engineering ethics education. Also, it aims to contribute to the quality improvement of engineering education to train engineers who can lead the society with responsibility as well as professional competence.

Prediction and Evaluation of Progressive Failure Behavior of CFRP using Crack Band Model Based Damage Variable (Crack Band Model 기반 손상변수를 이용한 탄소섬유강화 복합재료 적층판의 점진적 파손 거동 예측 및 검증)

  • Yoon, Donghyun;Kim, Sangdeok;Kim, Jaehoon;Doh, Youngdae
    • Composites Research
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    • v.32 no.5
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    • pp.258-264
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    • 2019
  • In this paper, a progressive failure analysis method was developed using the Hashin failure criterion and crack band model. Using the failure criterion, the failure initiation was evaluated. If the failure initiation is occurred, the damage variables at each failure modes (fiber tension & compression, matrix tension & compression) was calculated according to linear softening degradation behavior and the variables are used to derive the damaged stiffness matrix. The damaged stiffness matrix is reflected to damaged material and the progressive failure analysis is continued until the damage variables to be 1 that complete failure of material. A series of processes were performed using FE commercial code ABAQUS with user defined material subroutine (UMAT). To evaluate the proposed progressive failure model, the experimental results of open hole composite laminate tests was compared with numerical result. Using digital image correlation system, the strain behavior also was compared. The proposed numerical results were coincided well with the experimental results.