• Title/Summary/Keyword: Cost control

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VSI ${\overline{X}}$-CRL 합성관리도의 경제적 설계 (Economic design of VSI ${\overline{X}}$-CRL Synthetic Control Chart)

  • 송서일;박현규;정혜진
    • 산업경영시스템학회지
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    • 제28권4호
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    • pp.85-93
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    • 2005
  • This paper is designed a VSI ${\overline{X}}$-CRL synthetic control chart in aspect of economy. We found the optimal sampling interval and various control limit factors under various cost parameters using cost function, proposed Lorenzen and Vance. Optimal design parameters include the sample size, control limit width, sampling interval, CRL/S chart control limit; L. Comparison and analysis of cost parameters are applied between synthetic VSI ${\overline{X}}$-CRL chart and FSI ${\overline{X}}$-CRL chart. The result of this paper shows that VSI ${\overline{X}}$-CRL chart brings cost-cutting effect of 3.04% control expense less than FSI control chart. It may not be difficult to establish the optimal economic control parameters to apply the practical cost parameters in the field.

The Effects of Imprecise Measurement on the Economic Asymmetric $\bar{X}$ and S Control Charts

  • Yang, Su-Fen
    • International Journal of Quality Innovation
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    • 제3권2호
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    • pp.46-56
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    • 2002
  • The presence of imprecise measurement may seriously affect the efficiency of process control and production cost. A cost model is derived to determine the design parameters of the economic asymmetric $\bar{X}$ and S control charts including measurement errors. The effects of imprecise measurement on the performance of the economic asymmetric $\bar{X}$ and S control charts and production cost are examined for the case where the process mean and process standard deviation may change. Application of the proposed control charts is demonstrated through an example. Numerical examples illustrate the effects of imprecise measurement on the design parameters of the proposed control charts. It shows that the imprecision measurement may seriously affrct the ability of the proposed control charts to detect process disturbances quickly, change the sampling frequency, and increase the production cost compared to the control charts excluding measurement errors.

종합건설사 현장의 원가초과 억제 방안 분석에 관한 연구 (A Study on General Contractors' Control Measures for Construction Cost Overrun)

  • 박지영;김현진;김한수
    • 한국건설관리학회논문집
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    • 제25권3호
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    • pp.27-36
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    • 2024
  • 원가초과의 억제는 건설기업의 수익성 확보를 위해 매우 중요한 현안이다. 특히 원자재 가격 상승, 고금리 정책에 따른 금융비용 상승 등과 같이 원가 상승 압박이 큰 상황에서 실패비용 발생으로 인한 원가초과는 건설기업의 수익성에 매우 부정적인 영향을 미친다. 본 연구의 목적은 IPA기법을 활용하여 건설기업이 현장에서 채택하고 있는 원가초과 억제 방안의 현황을 분석하고 주요 특징 및 시사점을 제시하는 데 있다. IPA 분석 결과, 종합건설사 실무자들은 원가초과에 대한 관심과 노력 수준은 높지만 그 성과는 상대적으로 낮은 것으로 나타났다. 그럼에도 불구하고 대체적으로 원가초과를 억제하기 위해 중요하다고 생각하는 방안은 실행도 또한 높은 경향을 보이고 있었다. 중요도가 높지만 실행도가 낮게 나타나는 원가초과 억제 방안은 주로 협력 및 의사소통 부문에 속해있으며 원가초과의 억제를 위해서는 감리자/CM, 본사, 인허가 기관과의 협력 및 의사소통을 강화하는 것이 가장 시급한 것으로 나타났다. 본 연구를 통해 건설기업의 원가초과 억제 방안에 대한 현황과 개선점을 파악할 수 있으며, 이는 향후 원가초과 억제 전략 마련을 위한 방향성과 개선사항을 도출하는데 유용하게 활용될 수 있다.

건설재해 강도율 감소를 위한 안전관리비의 책정 및 사용방안 (The Appropriation and The Use Scheme of Safety Control Cost for Reducing Severity Rate of Injury on Construction)

  • 김병수
    • 대한토목학회논문집
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    • 제28권3D호
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    • pp.383-390
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    • 2008
  • 우리나라의 건설안전 관리시스템은 그동안 꾸준히 개선되어 왔으나 재해강도율은 감소되지 않고 있고 건설산업의 안전수준도 향상되지 못하고 있는 실정이다. 재해강도율을 감소시키기 위해서는 건설현장에서의 안전관리도 중요하지만 안전설계 의무화 및 설계 안전성 평가의 도입이나 건설업 산업안전보건관리비의 효과적인 사용방안 등 제도적인 틀을 개선하는 것이 필요하다. 그 중 안전관리비는 낙찰률에 따라 당초 설계금액보다 줄어드는 문제와 현장에서 사용시 안전관리자 등의 인건비에 비해 안전시설비용이 상대적으로 적게 집행되는 문제점이 있다. 본 연구는 건설업 재해강도율이 감소하지 않는 주요원인을 살펴보고 그 원인을 제거할 수 있는 방안으로 안전관리비와 관련된 문제점 분석을 통해 효과적인 개선방안을 제시함으로써 건설현장의 재해강도율을 낮추는데 기여하고자 한다.

구성요소치 해석을 이용한 확률계의 축소와 제어 (Stochastic System Reduction and Control via Component Cost Analysis)

  • 채교순;이동희;박성만;여운경;조윤현;허훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.921-926
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    • 2007
  • A dynamic system under random disturbance is considered in the study. In order to control the system efficiently, proper reduction of system dimension is indispensible in design stage. The reduction method using component cost analysis in conjunction with stochastic analysis is proposed for the control of a system. System response is obtained in terms of dynamic moment equation via Fokker-Plank-Kolmogorov(F-P-K) equation. The dynamic moment response of the system under random disturbance are reduced by using of deterministic version of component cost analysis. The reduced system via proposed "stochastic component cost analysis" is successfully implemented for dynamic response and shows remarkable control performance effectively utilizing "stochastic controller" in physical time domain.

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운전비 절감을 위한 빙축열시스템 냉동기 운전기법 평가 (An Evaluation of Chiller Control Strategy in Ice Storage System for Cost-Saving Operation)

  • 이경호;최병윤;이상렬
    • 설비공학논문집
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    • 제20권2호
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    • pp.97-105
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    • 2008
  • This paper presents simulated and experimental test results of optimal control algorithm for an encapsulated ice thermal storage system with full capacity chiller operation. The algorithm finds an optimal combination of a chiller and/or a storage tank operation for the minimum total operation cost through a cycle of charging and discharging. Dynamic programming is used to find the optimal control schedule. The conventional control strategy of chiller-priority is the baseline case for comparing with the optimal control strategy through simulation and experimental test. Simulation shows that operating cost for the optimal control with chiller on-off operation is not so different from that with chiller part load capacity control. As a result from the experimental test, the optimal control operation according to the simulated operation schedule showed about 14 % of cost saving compared with the chiller-priority control.

An Analysis of Cost Driver in Software Cost Model by Neural Network System

  • Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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    • pp.377-377
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    • 2000
  • Current software cost estimation models, such as the 1951 COCOMO, its 1987 Ada COCOMO update, is composed of nonlinear models, such as product attributes, computer attributes, personnel attributes, project attributes, effort-multiplier cost drivers, and have been experiencing increasing difficulties in estimating the costs of software developed to new lift cycle processes and capabilities. The COCOMO II is developed fur new forms against the current software cost estimation models. This paper provides a case-based analysis result of the cost driver in the software cost models, such as COCOMO and COCOMO 2.0 by fuzzy and neural network.

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Robust Guaranteed Cost Filtering for Uncertain Systems with Time-Varying Delay Via LMI Approach

  • Kim, Jong-Hae
    • Transactions on Control, Automation and Systems Engineering
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    • 제3권1호
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    • pp.27-31
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    • 2001
  • In this paper, we consider the guaranteed cost filtering design method for time-varying delay system with parameter uncertainties by LMI(Linear Matrix Inequality) approach. The objective is to design a stable guaranteed cost filter which minimizes the guaranteed cost fo the closed loop systems in filtering error dynamics. The sufficient conditions for the existence of filter, the guaranteed cost filter design method, and th guaranteed cost upper bound are proposed by LMI technique in terms of all finding variables. Finally, we give an example to check the validity of the proposed method.

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손실비용함수를 이용한 pn관리도의 경제적인 설계 (Economic design of a pn control charts using loss-cost function)

  • 이영식;황의철
    • 품질경영학회지
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    • 제18권1호
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    • pp.77-83
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    • 1990
  • A model for the economic design of an pn control charts with an assignale cause is presented and the loss-cost function for control schemes using these charts is derived. By minimizing this function with respect to the three control variables, namely, the sample size, the sampling interval and acceptance number, the economically optimal control plan can be optained. The article shows what influence increasing or decreasing condition, according to changeability of the size of these factors, of expected cost can have on the economy when an attribute control chart is used.

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Economic Evaluation of IT Investments for Emergency Management : A Cost-centric Control Model

  • Kim, Tae-Ha;Lee, Young-Jai
    • Journal of Information Technology Applications and Management
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    • 제15권3호
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    • pp.195-208
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    • 2008
  • In an emergency management case, evaluating the economic value of information technology investments is a challenging problem due to the effects of decision making, uncertainty of disasters, and difficulty of measurements. Risk assessment and recovery process, one of the major functions in emergency management, consists of (1) measurement of damages or losses, (2) recovery planning, (3) reporting and approving budgets, (4) auctioning off recovery projects to constructors, and (5) construction for the recovery. Specifically and of our interest, measurement of damages or losses is often a costly and time-consuming process because the wide range of field surveys should be performed by a limited pool of trained agents. Managers, therefore, have to balance accuracy of the field survey against the total time to complete the survey. Using information technologies to support field survey and reporting has great potential to reduce errors and lowers the cost of the process. However, existing cost benefit analysis framework may be problematic to evaluate and justify the IT investment because the cost benefit analysis often include the long-run benefit of IT that is difficult to quantify and overlook the impact of managerial control upon the investment outcomes. Therefore, we present an alternative cost-centric control model that conservatively quantifies all cost savings to replace benefits in cost benefit analysis and incorporate the managerial control. The model provides a framework to examine how managerial decision making and uncertainty of disaster affect the economic value of IT investments. The current project in Emergency Agency in South Korea is introduced as a case to apply the cost-centric control model. Our work helps managers to better evaluate and justify IT-related investment alternatives in emergency management.

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