• Journal of Integrative Natural Science
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• v.17 no.2
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• pp.43-51
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• 2024

Jung et al.(2015) suggest the two-phase warranty model, which is a general type of warranty model. 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. And warranty policies play a very important role in product marketing. In this paper, we suggest the optimal warranty policy for free extended two-phase warranty. To determine the optimal warranty period, we adopt the expected profit per unit product. So, the expressions for the total expected cost, the sale price and the expected profit per unit product from the manufacturer's point of view are derived. Also, we discuss the optimal warranty period and the numerical examples are provided to illustrate the proposed the warranty policy.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1557-1564
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• 2016

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 two stage maintenance policy under the non-renewing warranty from the user's point of view in this paper. In the first stage, the user has to decide whether or not to purchase the extended warranty period. And, in the second stage, the optimal replacement period following the expiration of the warranty is determined. Under the extended warranty, the failed system is minimally repaired by the manufacturer at no cost to the user. We utilize the expected cost from the user's perspective to determine the optimal two stage maintenance policy. Finally, a few numerical examples are given for illustrative purpose.

• 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 Applied Reliability
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• v.13 no.2
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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.

• Journal of Integrative Natural Science
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• v.14 no.4
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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.

• Korean Journal of Construction Engineering and Management
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• v.9 no.4
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• pp.66-74
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• 2008

Warranty contracting for pavements construction has been widely used in Europeans countries, Japan, and the U.S. and the benefits of warranty contract has been proven. This research investigated the European, U.S., and Japanese warranty contract policies and compared pros and cons. The most appropriate warranty contract policy solution is developed to fit in the Korean construction industry culture. Three main conclusions have been developed in this study: (1) performance specifications should be developed; (2) the systematic method is required to estimate the appropriate costs of performance bond and warranty period, etc.; and (3) short and long term plans for adopting performance warranty contract in Korea are suggested.

• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.195-202
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• 2018

The defects that are bound to arise in most construction projects cause disputes among the contracting parties regarding the defect warranty liability (DWL)guaranteed by the retention of the contractor's performance security at the end of the performance period of the contract. Most current projects involve a multiple-tier contractual relationship, causing the liability for some defects to overlap. In addition, many construction projects are made up of multiple detailed work types which an expert hired by the owner inspects the part completed by the contractor and pays an interim payment. However, after the completion of work, the contractor will still hold the defect warranty liability. In a scenario in which the work is delayed due to reasons for which the owner is responsible, the defect warranty liability period is also increased, imposing an additional burden on the contractor. In this study, basic research was carried out with the goal of reducing problems related to defect warranty liability Problems related to defect warranty liability cases and the nature of the defect warranty liability period were investigated. Possible solutions to the problems caused by the DWL that were suggested include the separation of the negligence liability period and the strict liability period, as well as the introduction of a retention money system.

• Journal of Applied Reliability
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• v.11 no.4
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.266-267
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• 2017

As apartment buildings defect lawsuits become socioeconomic problems, an objective basis system for the term of warranty liability of reinforced concrete constructions is urgent. This study was carried out as a basic study for developing a basis system for the term of warranty liability. To do this, defect data actual collected in apartment complexes were collected and analyzed. As the result of checking the cumulative rate of defect occurrence in reinforced concrete construction by year, the point of time of reaching the 90% level was the 5th years, which was similar with the provision of the Apartment Building Management Act. However, the current Supreme Court precedent has decided that the term of warranty liability for the main structural parts in reinforced concrete construction shall be 10 years and the dispute is expected to continue in the future in the defect lawsuit.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.245-246
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• 2015

Cases of lawsuit and conflict are increasing because of defects in apartments in use after the completion of construction. Further, with changes in the consciousness of residents and in the social environment, many residents are showing interest in defect-related lawsuits. However, the term of warranty liability defined in the current law is not practically appropriate, and the verification of the determination of the term of warranty liability is insufficient. Against this background, this research aims to evaluate the appropriateness of defect repair periods by examining the actual defect condition of the finishing work among the various defects related to apartments. Collected performance data are analyzed by statistical techniques by considering the defect occurrence rate per construction type and the construction year of the finishing work in apartment construction. The analysis results will be used as basic data for evaluating the appropriateness of the standards for the term finishing works warranty liability.