• 산업경영시스템학회지
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• 제19권39호
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• pp.89-98
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• 1996

This paper is concerned with cost analysis model in free -replacement policy under the periodic maintenance policy The free-replacement policy with minimal repairable item is considered as follows; in a manufacturer's view point operating unit is periodically replaced, if a failure occurs between minimal repair and periodic maintenance time, unit is remained in a failure condition. Also unit undergoes minimal repair at failures in minimal-repair interval. Then total expected cost per unit time is calculated according to maintenance period Tin a viewpoint of consumer's. The expected costs are included repair cost and usage cost: operating, fixed, minimal repair and loss cost. Numerical example is shown in which failure time of item has beta distribution.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권2호
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• pp.57-66
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• 2012

In this paper, we consider the periodic preventive maintenance model for a repairable system following the expiration of replacement-repair warranty. Under this 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 optimal periodic preventive maintenance policy is given for Weibull distribution case.

• 한국국방경영분석학회지
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• 제15권1호
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• pp.54-62
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• 1989

This paper presents a corrective maintenance model to determine either type of maintenance actions upon failure of the system. Types of maintenance actions considered are minimal repair and replacement. Minimal repair cost is assumed to be random, whereas replacement cost is fixed. A policy, B(t), which determines the type of maintenance action based on the estimated minimal repair cost when the system fails at time t is adopted. To obtain an optimal policy, an expected maintenance cost per unit time is derived and is minimized with respect to B(t).

• 디지털정책학회지
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• 1권1호
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• pp.21-26
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• 2022

본 연구에서는 요양병원이 입원비 지출 발생에 기여도가 큰점을 주목하여, 요양병원의 입원정책을 살펴보고, 불필요한 입원비발생을 유발한 점이 있다면, 해외사례를 참조하여 개선방안을 제안하고자 한다. 본 연구는 건강보험공단과 건강보험심사평가원에서 발행한 건강보험통계연보, 건강보험 주요통계를 주로 활용하여 연구를 진행하였다. 이를 바탕으로 요양병원이 입원비 발생에 가장 큰 기여를 한다는 것을 추론하였다. 본 연구 결과 요양병원의 입원규정이 명문화 되지 않았다는 문제점을 발견하였고, 명문화 되지않은 입원 기준이 불필요한 입원비 발생해 기여 할수 있다는 점을 발견하였고, 이를 극복하기 위한 개선방안을 우리보다 먼저 고령화를 경험한 미국의 사례에서 제안해보았다. 본연구를 시작으로 요양병원에서의 불필요한 입원비 지출을 줄인 보다 많은 외국의 사례들을 찾아야 할 것이다.

• 산업경영시스템학회지
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• 제24권62호
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• pp.1-10
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• 2001

The electronics industry is fast growing segment of manufacturing and service industries. It is important that the manufacturer develops a product with adequate life cycle, high quality, and low failure rate in the specified time period. Environmental Stress Screening(ESS) and burn-in are widely used in the electronic industry to assist in the elimination of early failure. In this research, we construct optimal cost model of combined ESS and burn-in under various warranty policy and establish optimal testing times for given environments. Also we conduct sensitivity analysis on various parameter. The results of this study are summarized as follows. Comparing free warranty policy to rebate warranty policy, optimal ESS time is longer under free warranty policy, and optimal burn-in time is longer under rebate warranty policy. Free warranty policy higher than rebate warranty policy in total cost.

• 보건행정학회지
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• 제20권4호
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• pp.45-57
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• 2010

Background : If different cost efficiency indexes were informed to the same clinic depending on the inclusion or exclusion of pharmacy cost, it may impair the reliability of provider-profiling system. This study aimed to investigate whether the omission of pharmacy cost affects cost-efficiency rankings in medical clinics. Methods : Data for ambulatory care cost at 23,112 medical clinics were collected from the claims database, which was constructed after review by the Health Insurance Review and Assessment Service (HIRA) of Korea in April 2007. We calculated two types of cost efficiency indexes by inclusion or exclusion of pharmacy cost for a medical clinic. The agreement between the decile rankings of the two indexes was also assessed using the weighted kappa statistic of Landis and Koch. Results : When the cost efficiency index for total cost including pharmacy cost was compared with the index for total cost excluding it, the agreement between the two indexes was only 55%. The agreements between the two indexes were relatively low within specialties which have larger pharmacy volume of total cost and lower correlation between total cost with or without pharmacy cost included than the average level of all the specialties. Conclusion : These results suggest that the omission of pharmacy cost may result in contradictory outcomes that may be confusing to a medical institution and may impair the reliability of provider-profiling systems. It is very important to standardize profiling criteria for the reliability of provider profiling system.

• 대한공간정보학회지
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• 제11권4호
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• pp.29-34
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• 2003

본 연구의 목적은 지리정보유통 활성화를 위한 가격정책 수립측면의 가격산정 기준을 제시하는데 있다. 가격정책은 공급자 측면과 사용자의 측면을 동시에 고려하였다. 본 연구에서 제안한 가격정책에서는 개발단계 비용은 매몰비용으로 산정하였으며, 유지관리 및 갱신비용은 지리정보를 사용하는 사용자에게 부과하였다. 지리정보의 배포비용은 사용매체에 따라 사용자에게 부과하며, 사용목적, 자료의 최신성에 따라 가격을 차등적용 하였다. 또한 지리정보를 유료로 제공하는데 있어 저작권료를 적용해야 한다는 가격정책을 제시하였다. 본 연구에서 수행된 각종 항목을 고려하여 가격산정 기준(안)을 제시하였으며, 이를 통해 지리정보 유통이 더욱 활성화 될 것으로 기대된다.

• 대한산업공학회지
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• 제36권2호
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• pp.108-116
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• 2010

The maintenance of a deteriorating system is often imperfect. Previous studies have shown that the imperfect preventive maintenance (PM) can reduce the wear out and aging effects of deteriorating systems to a certain level between the conditions of as good as new and as bad as old. In this paper, we employ the concept of the improvement factor in investigating two optimal PM policies; failure limit policy and periodic PM policy. We redefine the improvement factor model as a function of the cost of PM, using this concept, we derive the conditions of optimal PM policies and formulate expressions to compute the expected cost rate. Based on this information, the determination of the maintenance policies which minimize the cost rate is examined. Numerical examples for the Weibull distribution case are also given.

• 대한산업공학회지
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• 제34권4호
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• pp.425-432
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• 2008

While the Vendor-Managed Inventory(VMI) is a convenient inventory replenishment policy for the customer company, the supplier usually bears the burden of higher inventory and urgent shipments to avoid shortage. Recently some manufacturers begin to fix the production schedule for the next few days (such as three days). Utilizing that information can improve the efficiency of the VMI. In this study, we present a myopic optimization model using a mixed inter programming; and a heuristics algorithm. We compare the performance of the two proposed methods with the existing (s, S) reorder policy. We consider the total cost as the sum of transportation cost and inventory cost at the customer's site. Numerical tests indicate that the two proposed methods significantly reduce the total cost over the (s, S) policy.

• 품질경영학회지
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• 제30권4호
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• pp.94-105
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• 2002

In this paper, replacement problems for a deteriorating system are considered. In the system under consideration, the successive lifetimes after repair become shorter and shorter, while the consecutive repair times become longer and longer. More specifically, the lifetimes of the system form a nonhomogeneous Poisson process, whereas the consecutive repair times constitute a stochastically increasing geometric process. Optimal replacement policies for the long-run average cost rate and the steady state availability are considered. Also taking the cost and the availability into consideration at the same time, the properties of optimal policies under the Cost Priority Policy and the Availability Priority Policy are obtained.