• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5097-5106
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• 2010

Two perspectives on developing better decision capabilities for a warranty system can be identified: one involving the inclusion of a 'learning' module and the other the inclusion of a 'prioritization' capability. This paper demonstrates how a warning process can be included in a warranty system by coupling with a neural network's learning capabilities. In addition to the neural network, a method is employed for assigning priorities to warning criteria by using the analytic hierarchy process (AHP). Thus, it is possible to construct an integrated system with three components: the warranty system, the AHP module, and the neural network system. A case study is provided to enhance the accuracy of warning/detection judgment in a warranty system for automobile companies, having many factors related to the warranty system.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.773-781
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• 2013

Recently, an extended warranty of the system following the expiration of the basic warranty is becoming increasingly popular to the user. In this respect, we suggest a preventive maintenance model following the expiration of extended warranty with minimal repair warranty from the user's point of view in this paper. Under basic warranty and extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user. For the preventive maintenance model, we derive the expressions for the expected cycle length, the expected total cost and the expected cost rate per unit time. Also, we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the numerical examples are presented to illustrate the purpose when the failure time of the system has a Weibull distribution.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.101-109
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• 2010

Under the Civil Code and related law in Korea, the liability for defects after delivery belongs to the Contractor. However, various disputes have occurred in relation to the remedy of such defects and the compensation for damages, which are the main liability of a contractor in the event of defects. Despite court decisions regarding defect liability, many problems prevail in the real world. For this reason, this working-level research considers the introduction of a performance warranty contract system. To establish the system successfully, it is necessary to analyze the trend of various warranty cases in the US. Therefore, the warranty system of the US was first examined, and the effect of acceptance, notification and burden of proof, remedies under warranty clauses, and default termination were investigated and analyzed in this study.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.53
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• pp.1-12
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• 1999

A warranty cost analysis for new products have received a lot of attention. In contrast, there is hardly any literature on similar analysis for second-hand products. The market of second-hand products has been increasing and along with that the importance of warranties for second-hand products has also been increasing. However, warranty policies similar to new products are not economically acceptable to dealers. One needs to formulate new warranty policies and models to estimate expected warranty costs for second-hand products. This paper proposes one-dimensional cost sharing warranty policies and develops models at system level to analysis warranty cost for second-hand products sold with these policies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.3
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• pp.1-7
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• 2013

This paper is a case study of reliability assessment with field warranty data of Clutch Master Cylinder (CMC) in hydraulic clutch system. We estimate lifetime distribution using field warranty data which contain much useful information for understanding reliability of the system in the real-world environments. However, the estimated parameters are far from existing reference values, which seems to be caused right censored field warranty data. To modify the parameters, we use the information of the durability test which is performed to verify that the lifetime of the item meets the required level. After that, we can observe that the modified parameters are closer to the existing reference values. This case study shows a possible idea to supplement lack of right censored field warranty data and its applicability.

• Journal of Applied Reliability
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• v.12 no.4
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• pp.255-263
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• 2012

This paper considers the cost analysis from the manufacturer's point of view for renewing replacement and non-renewing repair warranty(RRNRW) of a repairable system. To do so, we consider the renewing replacement and non-renewing repair warranty, which is proposed by Jung(2011). To analysis the expected warranty cost from the manufacturer's perspective for renewing replacement and non-renewing warranty, we obtain the expected total warranty cost and the expected warranty length which are very important information for the manufacturer. Finally, the numerical examples are presented for illustrative purpose.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.71-79
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• 2012

In this paper, an evaluation of a product replacement ratio of irreparable items to the normally working ones is performed with a view to a warranty analysis. It is demonstrated that the replacement ratio during the warranty period can be estimated from the field data collected during the period of operation, and one can provide the management with a useful information regarding the appropriateness for the warranty period, which is vital to the product marketing strategy. Although warranty data usually take the form of multiply right censored interval data, the conventional reliability analysis method seems to be good enough as in this case. More sophisticated method such as warranty cost analysis and 2-dimensional warranty analysis is yet desired.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.587-596
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• 2008

This paper develops the optimal periodic preventive maintenance policies following the expiration of warranty: renewing warranty and non-renewing warranty. After the warranty period is expired, the system undergoes the PM periodically and is minimally repaired at each failure between two successive PMs. Firstly, we determine the expected cost rate per unit time and the expected downtime per unit time for the periodic PM model. Then the overall value function suggested by Jiang and Ji(2002) is applied to obtain the optimal PM period and the optimal PM number. Finally, the numerical examples are presented for illustrative purpose.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.301-307
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• 1998

This paper proposes free warranty interval for repairable items when the failure types of item are considered. Failure types are classified into major failure and minor failure. If major failure occurs during warranty period, the item is replaced and if minor failure occurs during warranty period, the item is minimally repaired. This paper determines the optimum free warranty interval which minimizes total expected cost of the free warranty cost model. Numerical example is shown in which failure time of item has weibull distribution.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.11 no.17
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• pp.55-65
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• 1988

This article suggests the costs analysis of resumer's view under the stepdown warranty is renewd whenever a failure occurs in the warranty period. And the general warranty policy is showed such as free replacement policy prorata warranty policy, hybrid warranty policy. In this respect case, the cost of consumer is also calculated. In order to study the cost analysis of consumer. "RENEWAL THEORY" is introduced and the cost of consumer is calculated.alculated.