• 통합자연과학논문집
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• 제14권4호
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• pp.197-204
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• 2021

Under the two-phase warranty, the warranty period is divided into two intervals, one of which is for renewing replacement warranty, and the other is for minimal repair warranty. Jung^[13] discusses the two types of extended two-phase warranty models. In this paper, we suggest the replacement model after the extended two-phase warranty that has been proposed by Jung^[13]. To determine the optimal replacement policy, we adopt the expected cost rate per unit time. So, the expressions for the total expected cost, the expected length of the cycle and the expected cost rate per unit time from the user's point of view are derived. Also, we discuss the optimal replacement policy and the uniqueness of the solution for the optimization. Furthermore, the numerical examples are provided to illustrate the proposed the replacement model.

• 산업경영시스템학회지
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• 제20권43호
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• pp.357-364
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• 1997

After the buyer purchases the product, the seller's role does not end. If the product fails to function properly before the end of the warranty period, the seller is responsible for its repair or replacement under the seller's warranty policy. There are two common types of warranty policies: the free replacement warranty and the rebate warranty. Under the free replacement warranty policy, replacement or repairs during the warranty period are provided by the seller free of charge to the buyer. Under the rebate warranty policy, a failed item is replaced by a new one or is repaired at a cost to the age of the failed item. The rebate warranty is most often used for items such as a battery or an automobile tire which wear out and must be replaced at failure. This paper proposes a easy way of estimating the warranty cost under the free replacement warranty policy assuming an exponential product failure function on repairable products.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.117-122
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• 2011

In this paper, we suggest the optimal replacement policy following the expiration of repair warranty when the cost of minimal repair depends on the age of system. To do so, we first explain the replacement model under repair warranty. And then the optimal replacement policy following the expiration of repair warranty is discussed from the user's point of view. The criterion used to determine the optimality of the replacement model is the expected cost rate per unit time, which is obtained from the expected cycle length and the expected total cost for our replacement model. The numerical examples are given for illustrative purpose.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권4호
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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.

• International Journal of Reliability and Applications
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• 제18권1호
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• pp.1-8
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• 2017

In this paper, we study an extended warranty model under minimal repair-replacement warranty (MRRW) which is suggested by Park, Jung and Park (2013). Under MRRW policy, the manufacturer is responsible for providing the minimal repair-replacement services upon the system failures during the warranty period. And if the failure occurs during the extended warranty period, only the minimal repair is conducted. Following the expiration of extended warranty, the user is solely responsible for maintaining the system for a fixed length of time period and replaces the system at the end of such a maintenance period. During the maintenance period, only the minimally repair is given for each system failure. The main purpose of this article is to suggest the extended warranty and replacement model with MRRW. Given the cost structures incurred during the life cycle of the system, we formulate the expected cost and the expected length of life cycle to obtain the expected cost rate.

• 산업경영시스템학회지
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• 제12권20호
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• pp.39-45
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• 1989

This article is concerned with cost analysis in product warranty policy. The warranty cost can be different according to warranty rate and warranty renewal policy. In this paper the stepdown warranty is used. The warranty renewal policy is considered when the warranty is received upon free replacement period as item failing. Assuming the non repairable item as one item is sold, investigated manufacturer's cost in stepdown warranty policy. Also manufacturer's cost is calculated in the free replacement. pro-rata. hybrid policy. Numerical example is given over Weibull time to failure distribution, comparing stepdown warranty policy with free replacement, pro-rata, hybrid one in the manufacturer's point of view. The sensitivity analysis of warranty cost according to the number of warranty period step is included.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권2호
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• pp.77-86
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• 2013

Recently, an extended warranty of a system following the expiration of the basic warranty is becoming increasingly popular to the user. In this respect, we suggest a replacement model following the expiration of extended warranty with minimal repair warranty from the user's point of view in this paper. Under extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user during the original extended warranty period. As a criterion of the optimality, we utilize the expected cost rate per unit time during the life cycle from the user's perspective and suggest the optimal replacement period after extended warranty. Finally, a few numerical examples are given for illustrative purpose.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권2호
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• pp.122-128
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• 2014

In this paper, we consider the periodic preventive maintenance model for a repairable system following the expiration of extended warranty under replacement-repair warranty. Under the replacement-repair warranty, the failed system is replaced or minimally repaired by the manufacturer at no cost to the user. Also, under extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user during the original extended warranty period. As a criterion of the optimality, we utilize the expected cost rate per unit time during the life cycle from the user's perspective. And then we determine the optimal preventive maintenance period and the optimal preventive maintenance number by minimizing the expected cost rate per unit time. Finally, the optimal periodic preventive maintenance policy is given for Weibull distribution case.

• 대한산업공학회지
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• 제22권2호
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• pp.247-253
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• 1996

This paper proposes a new two-dimensional warranty policy with replacement and repair regions and analyses the warranty cost under the new warranty policy. The product is sold under a two-dimensional warranty(usage and age) in which two regions exist : the failed product is replaced by the manufacturer in the replacement region or minimally repaired by the manufacturer in the repair region. The formula of the expected warranty cost under some assumptions about usage and failure is obtained. Numerical examples are studied.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권4호
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• pp.409-417
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• 2011

In this paper, we consider a replacement model following the expiration of warranty. In other words, this paper proposes the optimal replacement policy for a repairable system following the expiration of payable renewing replacement-non-renewing minimal repair warranty. The expected cost rate per unit time from the user's perspective is used to determine the optimality of the replacement policy. Thus, we derive the expressions for the expected cycle length and the expected total cost to obtain the expected cost rate per unit time. Finally, the numerical examples are presented for illustrative purpose.