• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.135-136
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• 2022

Defects caused by apartment houses have the term of warranty liability according to the enforcement ordinance of Acts of the Management of Apartment Houses. In case when defects occur during the term, free defect maintenance can be provided from the construction company. Yet, there occur conflicts between the construction company and residents, as to whether there occur defects or not. To resolve these conflicts, this study aimed to analyze construction classification and types that need managing, based on defects of apartment houses occurring during the term of warranty liability. This research analyzed 138,576 cases of data, as of five apartment house complexes. For the construction classification for defects of apartment houses, wooden flooring products accounted for the highest rate, followed by paper hanging, and wooden window. For the construction types of defects, torn/scratching took up with the highest rate, followed by the condition of defect in fixing and operating. In order to embody defects occurring during the term of warranty liability, into the visualization technique, this researcher utilized the word cloud method. This study will pursue the method for maintaining defects during the term of warranty liability, in the subsequent research, using the data that this research presented.

• Journal of Distribution Science
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• v.11 no.2
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• pp.23-33
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• 2013

Purpose - Numerous studies have tried to assess the role of a warranty as an explanatory instrument for product quality. While one study argued that manufacturers signal their superior quality to consumers by extending the duration of a warranty, quality is not necessarily related to warranty and a warranty for a short duration is a sign of high product quality. However, there are limitations to measuring product quality in terms of a single variable such as a warranty. Some other studies have evaluated the influence of brand power or value and price on the supposed quality of a product while the influence of warranty was found to be insignificant. Research design, data, methodology - The study analyzes the influence of brand power and the country of origin effect on consumers' perception of product quality in line with warranty and establishes a priority strategy. Especially, consumer experience has a significant influence on state of the art technology products like applied home electronics as these goods are generally quite expensive and consumers expend significant energy in purchasing them, so the associated warranty and brand can have a critical role in the decision making process. The price of the product was excluded in this discussion as it continually varies with the market share of the product. Results - The results of the analysis are as follows: First, each of the factors such as the standard of the warranty, brand power, and country of origin effect influences the degree of satisfaction of an individual. Second, the factors brand power and quality of the warranty interact both complementarily and synergistically at a time, depending on the brand power. As brand power is more significant, the degree of satisfaction is greater in case of products with low quality warranty compared to those with high quality warranty. Third, the brand power and country of origin effect present a complementary interaction. Fourth, the country of origin effect and quality of a warranty interact synergistically. Conclusions - Thus, the higher the quality of warranty, greater is the increment in the degree of satisfaction. The comprehensive study on the effect of the country of origin on the purchase decision process and the degree of satisfaction compared to the other elements shows that in case of Japanese and Korean markets the brand power of a company is desirable in sustaining the quality of warranty to the industrial average. Also, there is no significant improvement in the perceived quality of the product when the quality of the warranty is lowered. Therefore, the warranty effect diminishes when the value of the brand is known, while it perishes when both the brand power and the country of origin effect are strong enough.

• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.40-47
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• 2006

Claim history data of rather long period were collected to assess reliability and warranty cost analyses. The data were appropriately organized to be used for further statistical analyses. For each critical component, nonparametric statistical method was applied to obtain reliability plot. Hazard plots of the components in a subsystem or system level were also obtained. Competing risk model was assumed to obtain the performance of the subsystem or system level.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.4
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• pp.510-516
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• 1999

This paper proposes methods of estimating lifetime distribution from incomplete field data under parametric regression models. Failure-record data-failure times and covariates-reported to the manufacturer can be seriously incomplete for satisfactory inference since only reported failures are recorded. This paper assumes that within-warranty data are reported with probability $P_1$ ($\leq1$) and after-warranty data are reported with Methods of obtaining pseudo and after-warranty data are reported with $P_2$ (< $P_1$). Methods of obtaining pseudo maximum likelihood estimators(PMLEs) are outlined, their asymptotic properties are studied, and specific formulas for Weibull distribution are obtained. Simulation studies are perfumed to investigate the effects of follow-up percentage on the PMLEs.

• Journal of Information Technology Services
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• v.8 no.4
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• pp.175-185
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• 2009

Objectifying claims filed during the warranty period, analyzing the current circumstances and improving on the problem in question is an activity worth doing that could reduce the likelihood of claims to occur, cut down on the costs, and enhance the corporate image of the manufacturer. Existing analyses of claims are confronted with two problems. First, you can't precisely assess the risks of claims involved by means of the value of claims per 100 products alone. Second, even in a normal state, the existing approach fails to capture the probabilistic conflicts that escape the upper control limit of claims, thus leading to wrong control activities. To solve the first problem, this paper proposed that a time series detection concept where the claim rate is monitored based on the date when problems are processed and a hazard function for expression of the claim rate be utilized. For the second problem, this paper designed a model whereby to define a normal state by making use of PID (Proportion, Integral, Differential) and infer by way of a fuzzy concept. This paper confirmed the validity and applicability of the proposed approach by applying methods suggested in the actual past data of warranty claims of a large-scaled automotive firm, unlike hypothetical simulation data, in order to apply them directly in industrial job sites, as well as making theoretical suggestions for analysis of claims.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.762-766
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• 2002

This paper proposes a method or estimating lifetime distribution for products under two-dimensional warranty in which age and usage are used simultaneously to determine the eligibility of a warranty claim. For such a case, existing methods reduce the two-dimensional time stale to a single stale assuming that the two variables have a functional relationship. This assumption is, however, not appropriate since the functional relationship is unknown in practice. In this paper, the field age and usage data are modeled with a bivariate lifetime distribution. Method of obtaining maximum likelihood estimators is outlined, their asymptotic properties are studied and specific formulas for a bivariate Weibull distribution are obtained. The proposed model is compared with the existing one which assumes a lineal relationship between the two variables Simulation studios are performed to investigate the effect of the degree of dependency between the two variables.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.873-882
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• 2010

This paper considers a Bayesian approach to replacement policy following the expiration of non-renewing combination warranty. The non-renewing combination warranty is the combination of the non-renewing free replacement warranty and the non-renewing pro-rata replacement warranty. We use the criterion based on the expected cost and the expected downtime to determine the optimal replacement period. To do so, we obtain the expected cost rate per unit time and the expected downtime per unit time, respectively. When the failure times are assumed to follow a Weibull distribution with uncertain parameters, we propose the optimal replacement policy based on the Bayesian approach. The overall value function suggested by Jiang and Ji (2002) is utilized to determine the optimal replacement period. Also, the numerical examples are presented for illustrative purpose.

• Proceedings of the Safety Management and Science Conference
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• 2011.11a
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• pp.523-533
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• 2011

최근 들어 시스템이나 부품에 대한 고객의 요구조건이 다양해지고 제품책임과 품질보증 등의 사회적 요구가 점차 엄격해지고 있다. 이에 기업에서는 위험을 줄이고 제품의 합리적인 정보를 얻기 위해 제품 관련 보증데이터 수집 시스템을 구축하고 분석과 예측을 위한 다양한 연구가 진행되고 있다. 그러나 데이터 수집체계 구축에 많은 시간이 소요되고 데이터 유형에 따른 분석 방법에 익숙하지 못하여 데이터를 수집하고 분석하는 대에 어려움이 되고 있다. 본 연구에서는 보증데이터의 분석방법에 대한 연구 동향과 적용 현황을 조사하고, 보증데이터를 통한 효과적 분석방법과 활용방안을 모색 하고자 한다.

• Journal of Korean Society for Quality Management
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• v.40 no.1
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• pp.39-48
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• 2012

An early detection system for warranty issues periodically collects customers' claim data and automatically reports alarms about emerging issues based on statistical algorithms. It helps companies to reduce an issue definition time and save the handling cost of warranty claims. This paper provides an evaluation framework to validate the economic effect of an early detection system project. For this purpose, we present economical index of a project with explicit formulas such as ROI(return on investment), PP(payback period), NPV(net present value), PI(profitability index) and IRR(internal rate of return) and analyze the sensitivities of the index according to the variation of project input parameters. The proposed analysis framework is expected to be used for evaluating economic values of various system integration projects.

• Journal of Korean Society for Quality Management
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• v.39 no.2
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• pp.170-178
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• 2011

In general, a software fault detection phenonenon is described by a software reliability model based on a nonhomogeneous Poisson process(NHPP). In this paper, we propose a software reliability growth model considering the differences of the software environments in both the testing phase and the operational phase. Also, we consider the problem of determining the optimal release time and the optimal warranty period that minimize the total expected software cost which takes account of periodic software maintenance(e.g. patch, update, etc). Finally, we analyze the sensitivity of the optimal release time and warranty period based on the fault data observed in the actual testing process.