• Journal of the Society of Disaster Information
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• v.8 no.4
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• pp.328-335
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• 2012

The resource-based estimating based on standard unit price of construction work was estimated by multiplying the price per standard unit of work on the amount of labor, material, equipment use time. However, limitation of the resource-based estimating way does not adequately reflect the actual transactions prices. On the subject of water tunnel excavation as a new attempt to overcome these limitations, this study analyzed productivity by work type into cutter inspection/ exchange, TBM maintenance, TBM inspection/refueling, subsequent installations, tramcar, operating change, a cave-underground reinforcement / rock reinforcement, safety / meetings and analyzed actual cost estimating and the net advance rate based on this analysis result. Actual cost estimating calculation approach presented in this study can be utilized as a useful tool to predict the actual cost estimating in the TBM water tunnels field.

• KIEAE Journal
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• v.7 no.3
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• pp.31-37
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• 2007

Statistical analyses with actual data are used in estimating construction cost for many years, but collected data could include factors that distort analytical results, namely outliers. To enhance reliability in predicting construction cost, the methodology, which is able to identify outliers and determine how to manage them, is needed. Actual costs obtained from 22 construction projects were studied. It is found that there is substantial disparity between results considering outliers and results not considering ones. Therefore, it is to identify outliers and apply an optimum process in estimating construction cost when actual data is used in statistical analysis.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.212-215
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• 2008

When managers predict exact construction cost at early stage and design phase, they can reduce construction cost in a more efficient way than to predict at construction stage. But present of public construction cost estimation and management almost after the construction documents design phase. Therefore, construction cost management in the early stage and schematic design phase to generally use approximate estimating is not correct. Accordingly, this study analyze problem of current cost estimating method and a concrete cost plans make using case information of actual cost to analyze in schematic design phase. Possible to check going on the suitable design, this study conducts the preliminary research for the development of cost estimating model.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.488-493
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• 2013

Accurate initial cost estimates are essential to effective management of construction projects where many decisions are made in the course of project management by referencing the estimates. In practice, the initial estimates are frequently derived from historical actual cost data, for which standard distribution-based techniques are widely applied in the construction industry to account for risk associated with the estimates. This approach assumes the same probability distribution of estimate errors for any selected estimates. This assumption, however, is not always satisfied. In order to account for the probabilistic nature of estimate errors, an alternative method for measuring the risk associated with a selected initial estimate is developed by applying the Bayesian probability approach. An application example include demonstrates how the method is implemented. A hypothesis test is conducted to reveal the robustness of the Bayesian probability model. The method is envisioned to effectively complement cost estimating methods that are currently in use by providing benefits as follows: (1) it effectively accounts for the probabilistic nature of errors in estimates; (2) it is easy to implement by using historical estimates and actual costs that are readily available in most construction companies; and (3) it minimizes subjective judgment by using quantitative data only.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.383-386
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• 2001

The ability to make good cost overruns predictions is a very important aspect of in major construction project. The probabilistic cost models can provide more reliable than traditional cost models which have been used in korea to prepare Bill of Quantities, if the actual cost data are sufficient enough to analyze the trends of the variables. The paper considers non-deterministic methods in a cost estimate. The method(referred to as the 'Monte Carlo simulation' method) interprets cost data indirectly, to generate a probability distribution for total costs from the deficient elemental experience cost distribution. The objectives of this research is to develop a method to forecast the probabilistic total construction cost and the elemental work cost

• Korean Institute of Interior Design Journal
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• no.23
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• pp.68-73
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• 2000

The purpose of this research is to develop interior construction cost-estimating system at the early stage of the project. Though general construction estimates are typically in quantitative, interior construction should be in rather qualitative. Therefore, design-concerned cost-estimating methods should be developed to manage interior projects from the early statge. 30 estimates of VIP-Zone interior projects, were examined to develop the general type of composition and material classification. The cost has been classified by construction parts such as wall, ceiling, floor, and doors & windows and their treatments. The composition and material related estimating system (CMRES) was consisted of the unit average costs of classification and the variation coefficients. The CMRESS was verified by the case study, and the results sowed that the difference between the actual estimate and the CMRES was competitively confident.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.167-176
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• 2006

It was found that Korean Standard of Estimate which has been used as the only basis of cost estimate of public construction projects had some side effects such as jerry-build construction and over-estimation because it failed to reflect the current price and the state-of-the-art construction methods in a changing construction environment. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004. This paper presents analytic criteria and a process model for deducing more current and reasonable historical construction cost for contract items from not only previous contract prices but also all of the other bid prices that were not contracted. The procedure of estimating actual unit cost proposed in this paper focuses on the removal of abnormal values including strategically too low or high prices and the time correction. In addition, basic research is conducted for the correction of actual unit cost through the analysis of fluctuation of bid price depending on bidding types and rates of successful bid. It is anticipated that the effective use of the proposed process model for estimating actual unit cost would make the cost estimation more current and reasonable.

• Convergence Security Journal
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• v.13 no.5
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• pp.97-105
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• 2013

It is very important the government project should be supported by enough budget for proceeding. The insufficient budget by poor budget estimating uesd to bring about discontinuing for the project. This is originally caused by inaccuracy for cost estimating about system and evaluating for system requirements on the projet initial phase. The system requirements is technical requirements that converted the user needs and is needs for communicating between stakeholder and developer and manufacturer. Also the system requirements is the primary factor to make the project cost. The cost estimating is not easy due to complication of cost factors and an aberration between cost estimating and actual cost. Specially, on the project initial phase, shortage of detail information for project make more difficult to do cost estimating. This study proposes the architecture for validating proper system requirements by using cost estimations methodology on the project initial phase and shows the computer tool for simulating the proposed architecture.

• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.90-97
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• 2001

The paper considers non-deterministic methods of analysing the risk exposure in a cost estimate. The method(referred to as the 'Monte Carlo simulation' method) interprets cost data indirectly, to generate a probability distribution for total costs from the deficient elemental experience cost distribution. The Monte Carlo method is popular method for incorporating uncertainty relative to parameter values in risk assessment modelling. Non-deterministic methods, they are here presented as possibly effective foundation on which to risk management in cost estimating. The objectives of this research is to develop a computerized algorithms to forecast the probabilistic total construction cost and the elemental work cost at the planning stage.

• Korean Journal of Construction Engineering and Management
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• v.7 no.5
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• pp.159-166
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• 2006

It was found that Korean Standard of Estimate which has been used as the only basis of cost estimate of public construction projects had some side effects such as jerry-build construction and over-estimation because it failed to reflect the current price and the state-of-the-art construction methods in a changing construction environment. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004. This paper presents analytic criteria and a process model for deducing more current and reasonable historical construction cost for contract items from not only previous contract prices but also all of the other bid prices that were not contracted. The procedure of estimating actual unit cost proposed in this paper focuses on the removal of abnormal values including strategically too low or high prices and the time correction. In addition, basic research is conducted for the correction of actual unit cost through the analysis of fluctuation of bid price depending on bidding types and rates of successful bid. It is anticipated that the effective use of the proposed process model for estimating actual unit cost would make the cost estimation more current and reasonable.