• Title, Summary, Keyword: Life-Cycle Cost

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A Study on the Optimal Equipment Selection of Series Systems using Life Cycle Cost and Failure Cost (Failure Cost와 Life Cycle Cost를 고려한 연속시스템에 대한 최적 장치 선택에 관한 연구)

  • Jin Sang-Hwa;Kim Yong-Ha;Song Hee-Oeul;Yeo Yeong-Koo;Kim In-Won
    • Journal of the Korean Society of Safety
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    • v.19 no.4
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    • pp.55-59
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    • 2004
  • In this study, the required life cycle cost is evaluated in consideration of the equipment's availability during its lift cycle. In order to meet the maximum availability required by the process, the failure cost and life cycle cost is assessed The optimal equipment selection method is presented according to the analysis of the failure cost and life cycle cost. For the systems in which equipments are connected serially, the optimal equipments are selected by minimizing the life cycle cost and satisfying the required system availability goal. In addition, the selection methods and lift cycle cost are analyzed according to the cost variation of the equipment. By using the life cycle evaluation procedure, the failure cost and maintenance cost needed during the life cycle of the equipment can be presented.

Life Cycle Cost Analysis of Primary Cooling System by Systematic Support Cost (각종지원금제도에 의한 냉열원시스템의 라이프 사이클 코스트 분석)

  • Kim, C.M.;Jung, S.S.;Choi, C.H.
    • Journal of the Korean Solar Energy Society
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    • v.22 no.4
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    • pp.97-106
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    • 2002
  • The purpose of this study is to analyze the life cycle cost of primary cooling system by systematic support cost. Life Cycle Cost(LCC) is the process of making an economic assessment of an item, area, system, or facility by considering all significant costs of ownership over an economic life, expressed in terms of equivalent costs. The essence of life cycle costing is the analysis of equivalent costs of various alternative proposals. In order to select economical primary cooling system in early heat source plan stages, the research investigates cost items and cost characteristics during project process phases such as planning/design, construction, maintenance /management, and demolition/sell phases. The study also analyze the life cycle cost by capacity leading to suggest the most economical primary cooling system by systematic support cost.

A Study on the Life Cycle Cost Analysis of Railroad Bridges (철도교량의 생애주기비용분석에 관한 연구)

  • Park Mi-Yun;Na Ok-Pin;Hwang Young-Min;Kim Dae-Young;Cho Hyo-Nam
    • Proceedings of the KSR Conference
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    • pp.574-580
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    • 2005
  • Recently, the number of bridges and tunnels in railway is increasing due to the super high-speedy of train. Also, because of successively accidents of civil structures such as bridges and dams, the importance of maintenance become influential. The purpose of this study is to show the probabilistic life cycle cost analysis technique(PLCC) of the railroad bridge as pubic-infrastructures, and reasonably to indicate the economy in life cycle cost(LCC) through a case study. Rationally for life cycle cost analysis, the data gathered through many materials considered the uncertainty such as covariance. As a result, it is indicated that prestressed concrete bridge is pretty more cost-effective during life-cycle than preflex as well as steel box bridge. In future, if the construction of database and maintenance materials for railroad infrastructure is actualized, the life cycle cost analysis for railroad can be conducted easily and practically.

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Development of Life Cycle Cost Estimation Software on the Aspect of Maintenance Strategies (유지보수관점에서의 수명주기비용예측 소프트웨어 개발)

  • Jun, Hyun-Kyu;Kim, Jae-Hoon;Kim, Jong-Woon;Park, Jun-Seo
    • Proceedings of the KSR Conference
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    • pp.777-783
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    • 2007
  • Life cycle costing is one of the most effective cost approaches when we choose a solution from series of alternative so the least long-term cost ownership is achieved. Life cycle costing in railway industry has been focused on the prediction of investment for railway vehicles. But in today, the life cycle cost, LCC, prediction on the aspect of operation and maintenance cost through whole life cycle is highly necessary. In this paper, we present a strategy for the development of life cycle cost estimation software on the aspect of maintenance strategies of railway vehicle. For this purpose, we suggested a structure of LCC software based on the UNIFE LCC model. And we developed a pilot version of software to evaluate the LCC model that we suggested for railway vehicle. We performed LCC analysis on the brake module of metro vehicle in case study and concluded that the software and model developed in this research could enough to support engineers in choosing better cost effective solutions from many alternatives.

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Optimum Life Cycle Cost Design of Steel Box Girder Bridges (강상형교의 최적 Life Cycle Cost 설계)

  • 조효남;민대홍;김구선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.151-158
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    • 1998
  • This paper presents an optimal decision model for minimizing the life-cycle cost of steel box girder bridges. The point is that it takes into account service life process as a whole, and the life-cycle costs include initial (design, testing, and construction) costs, maintenance costs and expected failure costs. The problem is formulated as that of minimization of expected total life-cycle cost with respect to the design variables. The optimal solution identifies those values of the decision variables that result in minimum expected total cost. The performance constraints in the form of flexural failure and shear failure are those specified in the design code. Based on extensive numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on life-cycle cost approach proposed in this study provides a lot more rational and economical design, and thus the proposed approach will propose the development of new concepts and design methodologies that may have important implications in the next generation performance-based design codes and standards.

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Optimal Design of Bridge Substructure Considering Uncertainty (불확실성을 고려한 교량 하부구조 최적설계)

  • Pack, Jang-Ho;Shin, Young-Seok;Shin, Wook-Bum;Lee, Jae-Woo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.387-390
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    • 2008
  • The importance of the life cycle cost analysis for construction projects of bridge has been recognized over the last decades. Accordingly, theoretical models, guidelines, and supporting softwares have been developed for the life cycle cost analysis of bridges. However, it is difficult to predict life cycle cost considering uncertainties precisely. This paper presents methodology for optimal design of substructure for a steel box bridge. Total life cycle cost for the service life is calculated as sum of initial cost, damage cost considering uncertainty, maintenance cost, repair and rehabilitation cost. The optimization method is applied to design of a bridge substructure with minimal cost, in which the objective function is set to life cycle cost and constraints are formulated on the basis of Korean Bridge Design Specification. Initial cost is calculated based on standard costs of the Korea Construction Price Index and damage cost on the damage probabilities to consider the uncertainty of load and resistance. An advanced first-order second moment method is used as a practical tool for reliability analysis using damage probability. Maintenance cost and cycle is determined by a stochastic method and user cost includes traffic operation costs and time delay costs.

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The Effects of Slab Size on Pavement Life Cycle Cost

  • Parsons, Timothy A.;Hall, Jim W.Jr
    • International Journal of Highway Engineering
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    • v.8 no.2
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    • pp.49-54
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    • 2006
  • The purpose of this study was to determine the effect of expansion joint spacing (slab size) on the life cycle costs of owning Portland Cement Concrete (PCC) airfield pavements. Previous research has shown that slab size has a statistically significant impact on pavement performance. A probabilistic life cycle cost analysis was performed to determine if the effect of slab size on pavement performance would affect the total cost of ownership of PCC pavements. Data from 48 Pavement Condition Index (PCI) inspections of military and civilian airfields were used to develop probability-of-distress-by-condition curves, which were then used to develop probabilistic cost-of-repair-by-condition curves. A present worth life cycle cost analysis was then performed for various slab sizes, using construction costs, rehabilitation costs, and maintenance costs. Maintenance costs were determined by assuming a condition deterioration rate appropriate for each slab size and applying the cost-by-condition curves. The probabilistic cost-of-repair-by-condition curves indicated that smaller slabs are more expensive to repair on a unit cost basis. Life cycle cost analysis showed that larger slabs have a higher total cost of ownership than smaller slabs due to a faster rate of deterioration.

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Evaluation of Economy Feasibility for Bridge Superstructures Using LCC Optimal Design (LCC 최적설계를 황용한 교량 상부구조의 경제성 평가)

  • Ahn Ye-Jun;Lee Kwang-Kyun;Park Jang-Ho;Shin Young-Seok
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.549-556
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    • 2006
  • Life cycle cost is one of important factors in the evaluation of economy feasibility. Load carrying capacity curves for girders and decks are derived on the basis of bridge diagnostic results and condition grade curves to determine the service life and life cycle profile. The total life cycle costs including initial cost, damage cost, maintenance cost, user cost, and etc for the service life are calculated for steel box girder, PSC-I girder and rationalized plate girder. The optimal designs are performed for various service lifes and different superstructure types. The effects of parameters on the life cycle cost are investigated and the economy feasibility is evaluated through the sensitivity analysis.

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Optimal Design of PSC-I Girder Bridge Considering Life Cycle Cost (생애주기비용을 고려한 PSC-I형 교량의 최적설계)

  • Park, Jang-Ho;Shin, Yung-Seok
    • Journal of the Korean Society of Safety
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    • v.24 no.5
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    • pp.48-56
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    • 2009
  • This paper presents the procedure for the optimal design of a PSC-I girder bridge considering life cycle cost (LCC). The load carrying capacity curves for the concrete deck, PSC-I girder and $\pi$-type pier were derived and used for the estimate of service lives. Total life cycle cost for the service life was calculated as sum of initial cost, damage cost, maintenance cost, repair and rehabilitation cost, user cost, and disposal cost. The advanced First Order Second Moment method was used to estimate the damage cost. The optimization method was applied to the design of PSC-I girder bridge. The objective function was set to the annual cost, which is defined by dividing the total life cycle cost by the service life, and constraints were formulated on the basis of Korean Standards. The optimal design was performed for various service lives and the effects of design factors were investigated.

Life cycle analysis on correlation relationship between GHG emission and cost of electricity generation system for energy resources (전과정을 고려한 에너지 자원별 전력생산의 온실가스 배출량과 비용의 상관관계 분석)

  • Kim, Heetae;Ahn, Tae Kyu
    • 한국신재생에너지학회:학술대회논문집
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    • pp.136.2-136.2
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    • 2011
  • In this work, we analyzed correlations between life-cycle greenhouse gas (GHG) emissions and life-cycle cost of energy resources. Energy resources studied in this paper include coal, natural gas, nuclear power, hydropower, geothermal energy, wind power, solar thermal energy, and solar photovoltaic energy, and all of them are used to generate electricity. We calculated the mean values, ranges of maximum minus minimum values, and ranges of 90% confidence interval of life-cycle GHG emissions and life-cycle cost of each energy resource. Based on the values, we plotted them in two dimensional graphs to analyze a relationship and characteristics between GHG emissions and cost. Besides, to analyze the technical maturity, the GHG emissions and the range of minimum and maximum values were compared to each other. For the electric generation, energy resources are largely inverse proportional to the GHG emission and the corresponding cost.

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