• Title/Summary/Keyword: Unit Cost Model

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Maintenance Model of Multi-Component System Considering Characteristics of Components (부품특성(部品特性)을 고려한 다부품장비(多部品裝備)의 정비모형(整備模型))

  • Jeong, Yeong-Bae;Hwang, Ui-Cheol
    • Journal of Korean Society for Quality Management
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    • v.17 no.1
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    • pp.1-10
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    • 1989
  • In general, the characteristics of components which consist of multi-component system can not be the same. This paper proposes a maintenance model of multi-component system considering the characteristics of each component. In this paper, multi-component system is divided into three components-critical unit, major unit and minor unit, respectively. This paper determines the optimal replacement time of the system which minimizes total maintenance cost, optimal replacement period of major unit and initial stock quantity of minor unit within this optimal replacement time. Numerical examples are shown when the failure times of each unit have gamma distribution.

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Power Cost Analysis of Go-ri Nuclear Power Plant Units 1 and 2

  • Chung, Chang-Hyun;Kim, Chang-Hyo;Kim, Jin-Soo
    • Nuclear Engineering and Technology
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    • v.8 no.2
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    • pp.101-116
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    • 1976
  • An attempt is made to analyze the unit nuclear power cost of the Go-ri units 1 and 2 in terms of a set of model data. For the calculational purpose, the power cost is first decomposed into the cost components related to the plant capital, operation and maintenance, working capital requirements, and fuel cycle operation. Then, POWERCO-50 computer code is applied to enumerate the first three components and MITCOST-II is used to evaluate the fuel cycle cost component. The specific numerical results are the fuel cycle cost of Go-ri unit 2 for three alternative fuel cycles presumed, levelized unit power cost of units 1 and 2, and the sensitivity of the power cost to the fluctuation of the model data. Upon comparision of the results with the power cost of the fossil power plants in Korea, it is found that the nuclear power is economically preferred to the fossil power. Nevertheless, the turnkey contract value of Go-ri unit 2 appears to be rather expensive compared with the available data on the construction cost of the PWR plants. Therefore, it is suggested that, in order to make the nuclear power plants more attractive in Korea, the unfavorable contract of such kind must be avoided in the future introduction of the nuclear power plant. Capacity factor is of prime importance to achieving the economic generation of the nuclear electricity from the Go-ri plant. Therefore, it is concluded that more efforts should be directed to make the maximum use of the Go-ri plant.

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Modified Wu and Clements-Croome's PM model (수정된 Wu와 Clements-Croome의 예방보전 모형)

  • Jung, Ki Mun
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.4
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    • pp.791-798
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    • 2014
  • Wu and Clements-Croome (2005) suggest the preventive maintenance (PM) model with random maintenance quality. They assume that each PM resets the failure rate to zero and the rate of increases of the failure rate gets higher after each additional PM. However a system may not be restored to as good as new immediately after the completion of PM. Thus, this paper modifies the Wu and Clements-Croome's PM model and then the optimal PM policy is suggested. To determine the optimal PM policy, we utilize the expected cost rate per unit time for our model. That is, we obtain the optimal number and the optimal period by minimizing the expected cost rate per unit time. The numerical examples are presented for illustrative purpose.

Efficient Operation Policy in a Closed-loop Tire Manufacturing System with EPR

  • Ko, Young-Dae;Hwang, Hark
    • Industrial Engineering and Management Systems
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    • v.8 no.3
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    • pp.162-170
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    • 2009
  • This paper deals with a closed-loop remanufacturing system with one manufacturer and one remanufacturer. The manufacturer sells new products bearing the 'Extended Producer Responsibility (EPR).' It is assumed that the manufacturer's collection rate of used products depends only on the buy-back cost, while that of the remanufacturer depends on the minimum allowed quality level of used products in addition to the buy-back cost. Through the development of mathematical models with the objective function of maximizing profit, we study an efficient operation policy of each party. The decision variables are the unit selling price of new products and remanufactured products, the unit buy-back cost of the used products of the manufacturer and remanufacturer, and the minimum allowed quality level. The validity of the model is examined through numerical examples and sensitivity analysis.

A Bayesian Approach to Replacement Policy Based on Cost and Downtime

  • Jung, Ki-Mun;Han, Sung-Sil
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.3
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    • pp.743-752
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    • 2006
  • This paper considers a Bayesian approach to replacement policy model with minimal repair. 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 time is Weibull distribution with uncertain parameters, a Bayesian approach is established to formally express and update the uncertain parameters for determining an optimal maintenance policy. Especially, the overall value function suggested by Jiagn and Ji(2002) is applied to obtain the optimal replacement period. The numerical examples are presented for illustrative purpose.

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A Corrective Maintenance Policy Which Determines Replacement or Repair for the Maintenance of System Failures

  • Jang, Jae-Jin;Lie, Chang-Hoon
    • Journal of the military operations research society of Korea
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    • v.15 no.1
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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).

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Development of a Hospital Service-based Costing System and Its Application (병원서비스별 원가분석모형의 개발과 적용)

  • 박하영
    • Health Policy and Management
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    • v.5 no.2
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    • pp.35-69
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    • 1995
  • The managerial environment of hospitals in Korea characterized by low levels of medical insurance fees is worsening by increasing government regulations as to the utilization of medical services, rising costs of labor, material, and medical equipments, growing patient expectations concerning the quality of services, and escalating competitions among large hospitals in the market. Hospitals should seek for their survival strategies in this harsh environment and they should have information about costs of their products in doing so. However, it has not been available due to the complexity of the production process of hospital services. The objectives of this study were to develop a service-based cost accounting model and to apply the developed model to a study hospital to obtain cost information of hospital services. A model commonly used for the job-order product cost accounting in the manufacturing industry was modified for the use in hospitals in Korea. Actual costs, instead of standard costs, incurred to produce a unit of services during a given period of time were estimated in the model. Data required to implement the model included financial information, statistics for the allocation of supportive cost center costs to final cost centers, statistics for the allocation of final cost center costs to services, and the volume of each services charged to patients during a study period. The model was executed using data of a university teaching hospital located in Seoul for the fiscal year 1992. Data for financial information, allocation statistics fo supportive service costs, and the volume of services, most of them in electronic form, were available to the study. Data for allocation statistics of final cost center costs were collected in the study. There were 15 types of evaluation and management service, 2, 923 types of technical service, and 2, 608 types of drug and material service charged to patients in the study hospital during the fiscal year 1992. Labor costs of each of seven types of pesonnel, material costs of 611 types of drugs and materials, and depreciation costs of 212 types of medical equipments, miscellaneous costs, and indirect costs incurred in producing a unit of each services were estimated. Medical insurance fees for basic services such as evaluation and management of inpatients and outpatients, injection, and filling prescriptions, and for operating procedures were found to be set lower than costs. Infrequent services which use expensive medical equipments showed negative revenuse as well. On the other hand, fees for services not covered by the insurance such as CT, MRI and Sonogram, and for laboratory tests were higher than costs. This study has a significance in making it possible for a hospital to obtain cost information for all types of services which produced income based on all types of expenses incurred during a given period of time. This information can assist the management of a hospital in finding an effective cost reduction strategy, an efficient service-mix strategy under a given fee structure, and an optimum strategy for within-hospital resource allocations.

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An Estimation Model of Historical Cost Using BIM Library for Road Project (도로분야 BIM 라이브러리를 활용한 실적공사비 산정모델 구축)

  • Moon, HyounSeok;Ju, KiBeom
    • Korean Journal of Computational Design and Engineering
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    • v.20 no.4
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    • pp.431-442
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    • 2015
  • Currently, a BIM-based quantity takeoff (QTO) system is mainly focused on architectural projects. To perform this, diverse quantity takeoff methods such as an object-based automatic quantity takeoff, manual quantity and base functions of calculation have widely been utilizing. However, since BIM library for road projects includes structural elements associated with alignment, it is necessary to establish cost estimation system interlocked with historical cost using 3D library by each unit length. Accordingly, the aim of this study is to develop cost estimation model with using a historical cost approach so that it can be utilized in construction planning based on the BIM library for road projects. For this, based on the BIM library for road, the standardized quantity is estimated, and a process for calculating historical cost and a verification model with a 5D simulation was developed by mapping a WBS code with each BIM library object. This can be applied during the approximate cost estimation process in a project planning and an initial design phase for road projects. Besides, it is expected that these results will be utilized in constructing an optimal historical cost estimation process for project libraries.

Statistical Model for Analysing Variations in Inpatient Procedure and Operation Costs of Some Selected K-DRGs by Type of Hospitals (일부 K-DRG 환례의 의료기관 유형별 수술 및 처치 진료비의 변이 분석 모형)

  • Lee, Young-Jo;Noh, Maeng-Seok;Kim, Yoon;Lee, Moo-Sang;Lee, Sang-Il
    • Health Policy and Management
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    • v.8 no.1
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    • pp.1-14
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    • 1998
  • Analysis of practice variations has been one of important issues in trying to contain costs as well as to manage quality in health care. This study was conducted to provide statistical model for analysing variations in inpatient costs by type of hospitals. Four K-DRGs including Cesarean section, appendectomy, cataract extraction, and pediatric pneumonia with CC class 0 were selected, and means and dispersions of inpatient procedure and operation costs were simultaneously compared between type of hospitals. The results indicated that joint modelling of means and dispersions by gamma distribution was a very useful analytic tool for identifying factors which might have relationship with variations in inpatient costs. This model can be expanded to test the significance of several independent variables in analysing cost variations. In surgical conditions, means and unit variations of procedure and operation costs showed consistent pattern which was tertiarty hospital, general hospital, and hospital in descending order. Different findings were identified in pediatric pneumonia, from which mean and unit variation of procedure and operation cost was the highest in general hospital. The practical implication of this difference could not be drawn from this study. It will be done by further sophisticated researches. In order to develop health policy for cost containment and quality management in Korea, it is essential to find out manageable factors affecting variations in practice patterns which include characteristics of population, providers, regions, and so on. The statistical model presented in this study will give health services researchers useful insights for future investigations in analysing cost variations.

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PM Policy with Random Maintenance Quality Following the Expiration of Non-Renewing Warranty (비재생보증이 종료된 이후의 확률적 보전효과를 갖는 예방보전정책)

  • Jung, Ki-Mun
    • Communications for Statistical Applications and Methods
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    • v.15 no.1
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    • pp.77-86
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    • 2008
  • This paper develops the optimal periodic preventive maintenance policy following the expiration of non-renewing warranty. We assume that Wu and Clements-Croome's (2005) periodic PM model with random maintenance quality is utilized to maintain the system after the non-renewing warranty is expired. Given the cost structure to the user during the cycle of the product, we drive the expressions for the expected cost rate per unit time. Also, we obtain the optimal number and the optimal period by minimizing the expected cost rate per unit time. The numerical examples are presented for illustrative purpose.