• Plant Journal
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• v.8 no.4
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• pp.45-54
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• 2012

Estimated project cost and executed sensitivity analysis for domestic 500 MW coal-fired power plants with monte carlo simulation. As a result of research, the basis of constant price in December, 2011 and 95% level of confidence, the project cost in case of not having adjacent power plant was 1,870 billion won to 2,330 billion won and the project cost in case of having adjacent power plant was 1,240 billion won to 1,590 billion won. In case of not having adjacent power plant is sensitive to civil construction cost but the other case is sensitive to material cost.

• New & Renewable Energy
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• v.8 no.3
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• pp.23-29
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• 2012

LCOE of 11 Korean PV projects, total capacity of 44 MW, were calculated for each project being larger than 1 MW respectively. 9 out of 11 projects were constructed in 2008 under FIT scheme revealed that average LCOE is 600 Korean Won per kilowatt-hour and it becomes reduced to 348 Korean Won per kilowatt-hour for 2 projects that are constructed under RPS scheme in 2012. During the period between 2008 and 2012, installation cost per megawatt became 55% of 2008 value with operation and maintenance cost lowered to 80% while LCOE became only 58% due to reduced project size and lower irradiation for later projects. However, it is found that the ratio of LCOE / unit installation cost looks relatively constant, so that it can be used as an auxiliary parameter to gauge learning effect of BOS portion of a PV project.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.641-648
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• 2007

To develop a dynamic system project in which the requirement changes frequently, it's impossible to finish the development within a fixed-cost due to additional budget occurring in need of requirement creep. To manage the successive project within a fixed-cost, it's better to manage the ratio of necessarily changed size of project and necessary optional requirement. According to Bhagwat, it is occurred in the construction phase. Also, he stated that the software development cost, construction phase cost and requirement cost are equal and it was wrong explanation in the ratio of requirement creep and optional requirement. This paper assumes the requirement creep to be happening in the phase of elaboration and construction. In addition, some differences were supposed to happen between software development cost, construction phase cost, and requirement creep cost. As a result, the reality was preferred rather than the ratio of optional requirement and the ratio of requirement creep.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.534-541
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• 2011

Risk evaluation approaches for bidding on international construction projects are typically partitioned into three stages: country selection, project classification, and bid-cost evaluation. However, previous studies are frequently under attack in that they have several crucial limitations: 1) a dearth of studies about country selection risk tailored for the overseas construction market at a corporate level; 2) no consideration of uncertainties for input variable per se; 3) less probabilistic approaches in estimating a range of cost variance; and 4) less inclusion of covariance impacts. This study thus suggests a three-staged risk evaluation model to resolve these inherent problems. In the first stage, a country portfolio model that maximizes the expected construction market growth rate and profit rate while decreasing market uncertainty is formulated using multi-objective genetic analysis. Following this, probabilistic approaches for screening bad projects are suggested through applying various data mining methods such as discriminant logistic regression, neural network, C5.0, and support vector machine. For the last stage, the cost overrun prediction model is simulated for determining a reasonable bid cost, while considering non-parametric distribution, effects of systematic risks, and the firm's specific capability accrued in a given country. Through the three consecutive models, this study verifies that international construction risk can be allocated, reduced, and projected to some degree, thereby contributing to sustaining stable profits and revenues in both the short-term and the long-term perspective.

• Journal of KIBIM
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• v.7 no.2
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• pp.16-24
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• 2017

It is very important to estimate accurate construction total cost needed early in the project. In the initial phase of the design, the project cost estimates are determined by total quantity from design documents and the variables that affect the calculation of the total cost of the project. In order to determine accurate total construction cost, the contractor has to produce detailed quantity information based on the drawings and specifications. The process of preparing quantification and cost estimation documents is still being worked out manually, and a lot of errors have been occurred in many cases. Recent advances in information technology have led to the BIM based quantity takeoff and cost estimation. However, there are some limits to the extent to which the current specifications for BoQ documents are computed from BIM model. This research analyze the current BoQ cases and analyze how to make quantity takeoff possible through BIM. The study defined five levels of quantity category that could be produced by BIM. Only about 40% or indirectly usable items can be used when information is extracted to BIM modelling. This is very insufficient to fill out the BoQ. The BoQ document structure quantity takeoff specifications should be simplified in order to BIM based cost estimation more efficiently.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1608-1614
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• 2009

In recent days, the study of urban regeneration has been conducting with purposeful and sincere intent starting out with the residential environment improvement works. Within the range of urban regeneration, the low-cost housing technology means development of totally-integrated housing technology that may be applied to the regeneration project, especially for the rundown areas where infrastructure facilities in the urban zone have been degraded and obsoleted. In line with this, among many and varied methods in order for realization of the low-cost housing as a part of urban regeneration project, this study should like to propose an improvement methods of the key technologies in relation to the construction works by type of work with which construction costs (directing cost) would be reduced. And, in order to elicit the method for element technology that has been developed and improved in the most optimal manner centering on the selected construction work by the type of work, the researcher conducted comparative review of summary of element technologies related to the construction works concerned, characteristics, and construction method thereof. In particular, the researcher investigated the expenses (construction cost and labor cost), constructions (contractibility and productivity), safety, quality of works, and the technical status in environmental aspects, and the researcher also conducted analyses and evaluations thereof.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.479-487
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• 2013

State Highway Agencies (SHAs) have started utilizing cost-plus-time bidding (A+B bidding) since Federal Highway Agency (FHWA) declared it operational on May 4, 1995. Although this technique has successfully accelerated many projects by incorporating construction time in the bidding competition, a framework to illustrate the interactions of incentive/disincentive (I/D) rates on the competitiveness of contractors participating in the bid competition is yet to be developed. In a previous research, authors indicated that for each bid competition there is an efficient cap for I/D rates which are dictated by the capabilities of contractors in project acceleration. However, the results of previous study were based on the assumption that there is a statistically significant relationship between cost and time. In this study, the entire cost-plus-time projects implemented by the Oklahoma Department of Transportation (ODOT) were investigated. Then the significance of relationship between cost and time were analyzed for each contractor utilizing Analysis of Variance (ANOVA) technique, and the price-time function of each contractor was determined by regression analysis. The results of the analysis indicate that there is a significant relationship between cost and time for the majority of contractors. However, a quadratic relationship is not always significant and for some contractors a linear price-time relationship is significant. The results of this project can be used not only by ODOT to optimize the incentive/disincentive rates but also by contractors to determine the most competitive strategies of other bid participants.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.256-261
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• 2011

Labor productivity is a significant factor related to control time, cost, and quality. Many researchers have developed models to define method of measuring the relationship between productivity and various constraints such as the size of working area, maximum working hours, and the crew composition. Most of the previous research has focused on estimating productivity; however, this research concentrates on estimating labor productivity and developing time and cost data for repetitive concrete pouring activity. In Korea, "Standard Estimating" only contains the average productivity data of the construction industry, and it is difficult to predict the time and cost of any particular project; hence, there are some errors in estimating duration and cost for individual activity and project. To address these issues, this research collects data, measures productivity, and develops time and cost data using labor productivity based on field conditions from the collected data. A probabilistic approach is also proposed to develop data. A case study is performed to validate this process using actual data collected from construction sites and it is possible that the result will be used as the EVMS baseline of cost management and schedule management.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.114-116
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• 2015

This paper presents a Stochastic Time-Cost Tradeoff analysis system (STCT) that identifies optimal construction methods for activities, hence reducing the project completion time and cost simultaneously. It makes use of schedule information obtained from critical path method (CPM), applies alternative construction methods data obtained from estimators to respective activities, computes an optimal set of genetic algorithm (GA) parameters, executes simulation based GA experiments, and identifies near optimal solution(s). A test case verifies the usability of STCT.

• Journal of the Korea Institute of Building Construction
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• v.10 no.2
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• pp.133-138
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• 2010

Conceptual cost is estimated with insufficient information at an early stage of a building construction project, resulting in an inevitable gap between conceptual estimated cost and real constructed cost. For a project to be successful, this gap must be managed to be lower than a reliable level. Therefore, the purpose of this study is to propose a structural process for managing the reliability of conceptual cost estimates at an early stage of a building construction project. In researching this study, conceptual cost estimate experts were interviewed,and a risk management process was studied. Reliability assessment and a review process for improving the quality of conceptual cost estimate and the planning strategy of reliability management based on previous similar projects were added to the present estimate process. The proposed reliability management process will improve the chances of a successful project, by helping to decrease the risk of conceptual estimated cost.