• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.315-316
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• 2021

The proportion of maintenance work has been increasing due to the recent aging of the infrastructure, but the standardized construction cost estimation standards are insufficient for this. In particular, reinforced concrete structures are being applied to many structures such as buildings and bridges, and various construction methods for maintenance of reinforced concrete structures are being developed and applied. In this study, we surveyed about the current status of the construction method for the maintenance work of reinforced concrete structures and analyze the factors of the revision of the construction cost estimate standard for the reinforced concrete structure maintenance.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.849-859
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• 2006

Earnings of domestic enterprises are expected a serious damage because the lowest cost bid system and the current cost estimate system. In 2005 average successful bid rate for the lowest cost bid project is below 60%, this is not reach at the operating budget of enterprise. Many problems such as illegal construction, low price subcontract, chain enterprise loss com in to practice because of low successful bid rate. In addition earnings of the enterprises expected to be the minimum, because of enlarge execution of the current cost estimate system. This study tries to lend assistance by giving alternative for the construction enterprise by presenting the bid system, investigate and compare foreign system with domestic and analyze correlation of the lowest cost bid and the current cost estimate system.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.133-137
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• 2017

Nuclear power plants in Korea are usually built based on a duplicated model; so the project cost data of the preceding unit can be used as reference when estimating the project cost for the succeeding unit. However, since the contracting method is oriented towards the price, empirical factors such as making top-down estimations using the reverse calculation method based on the completion cost of the preceding unit is dominant. In order to develop a project cost database to resolve such problems, the detailed cost boundary of the project cost data must be categorized by project and by system. This study proposes a method to connect the code of account with the base quantities and the IAEA account, and proposes a database structure for the development of a project cost estimation system. The estimation system developed in the future is expected to utilize the proposed project cost data structure.

• Journal of KIBIM
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• v.7 no.3
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• pp.11-20
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• 2017

BIM technology, which is widely used in the construction industry, has been introduced in various fields for the purpose of saving construction cost and reducing construction schedule. However, in the case of BIM-based cost estimate, there are various trials and errors in applying BIM technology which can be applied for calculating quantity and cost estimate. BIM-based cost estimate can improve the quantity accuracy and allow to easy modifications that were not expected in 2D-based construction process. However, for this purpose, it is necessary to take into consideration that interoperability between BIM data and cost information should be planed in advance. Besides, the definition of a BIM data specification is also required for the seamless data exchange and integrity in each phase of the construction process. Therefore, in this study, we propose a BIM - based cost estimation method and technology in each type of work applicable to the current domestic construction industry.

• Knowledge Management Research
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• v.6 no.1
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• pp.19-32
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• 2005

The reliability of technology valuation depends on, among other things, the reliability of the discount rate estimate. The weighted average cost of capital, generally accepted as discount rate, consists of cost of equity and cost of debt. The model used to estimate the cost of equity for publicly traded firms can not be used directly for small-sized venture firms. In addition, the estimation of cost of debt become very difficult, given the limited and volatile price history, because these small-sized venture firms do not have associated credit ratings. Since two kinds of cost of capital for the small-sized venture firms can not be estimated directly from market data, this study suggests statistical frame works for estimating unknown two kinds of cost of capital. The estimates of underlying cost of capital will help determine the size of appropriate discount rate with logical and scientific way when the technology valuation for small-sized venture firms is made. This study also suggests the necessity of the risk premium for the technology competitiveness to improve the estimation of the appropriate discount rate for small-sized venture firms.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.417-424
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• 2009

For a construction project to progress smoothly, effective cost estimation is vital, particularly in the conceptual and schematic design stages. In these early phases, despite the fact that initial estimates are highly sensitive to changes in project scope, owners require accurate forecasts which reflect their supplying information. Thus, cost estimators need effective estimation strategies. Practically, parametric cost estimates are the most commonly used method in these initial phases, which utilizes historical cost data (Karshenas 1984, Kirkham 2007). Hence, compilation of historical data regarding appropriate cost variance governing parameters is a prime requirement. However, precedent practice of data mining (data preprocessing) for denoising internal errors or abnormal values is needed before compilation. As an effort to deal with this issue, this research proposed a statistical methodology for data preprocessing and verified that data preprocessing has a positive impact on the enhancement of estimate accuracy and stability. Moreover, Statistically Preprocessed data Based Parametric (SPBP) cost models are developed based on multiple regression equations and verified their effectiveness compared with conventional cost models.

• 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.

• Journal of the Korea Institute of Building Construction
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• v.12 no.5
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• pp.528-538
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• 2012

With domestic construction projects becoming bigger, more specialized and more advanced, the construction industry is striving to improve quality and quantity, and is diversifying functions and shapes. Nevertheless, the process of a construction project causes problems when we estimate construction price, because the cost breakdown structures are different in each step. The primary aim of this study was to estimate building life cycle cost using the Delphi method. The cost breakdown structure for life cycle cost was classified into planning, design, construction, maintenance and waste disposal, and each detailed classification was determined by estimating life cycle cost. Moreover, the developed cost breakdown structure is verified by consulting with experts to secure objectivity and validity.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.194-202
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• 2011

Most of Orders of Magnitude estimate are based on historical data. This data is converted to the current price using by the cost index method mainly. This method, however, is rarely utilized or only for one-time use due to the lack of data and the complex escalation calculation method. This paper present a typical process on the conceptual investment cost estimation using by Cost Indexes based on the actual case for the Train Control facility of High-speed rail project. The result is expected to serve as both an easy way for Order of Magnitude estimate and a standard guideline for computerized modeling.