• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.50-57
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• 2009

The Korea Standard of Estimate which has been used as the only basis of Cost estimate of public construction projects is failed to reflect the fluctuation of current construction cost. Therefore, the government decided to gradually introduce historical construction cost into cost estimate of public construction projects from 2004 and to reduce the use of Korean Standard of Estimate. This paper presents a series of process and the methodology for computing Actual Cost and analyzing the fluctuation patterns based on not only previous contract prices which made a successful bid but also all of the other bid prices. Also, this paper mainly handles a device for extracting strategic bid price such as low price bid for assuring reliable data and for predicting the construction cost which is built by Wavelet Analysis of Time series Analysis data and Neural Network. It is anticipated that the effective use of the proposed process for estimating actual unit cost would make the cost estimation more current and reasonable.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.20-36
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• 2022

This study aims to provide basic data for high-quality street tree management by setting reasonable management items and appropriate unit prices by reviewing the adequacy of current street tree management. Currently, street tree management items, except for street tree pruning, use general landscape tree quantity per unit for the street tree management quantity per unit. KEPCO (Korea Electric Power Corporation) applied pruning items from standard electric production infrastructure and carried out the activities at an average unit price of 51% lower for heavy pruning and 39% lower for light pruning than the standard estimate. This was judged to be a level that could not maintain or increase the quality of street tree management. It was determined that an appropriate standard unit price for street tree management was necessary. To improve the quantity per unit for the proper management of street trees, it was necessary to review costs in the field. However, due to the absence of data on actual construction costs in the domestic landscape field, detailed items of the US RSMeans Building Construction Cost Data (RSMeans) were reviewed, and the actual construction costs were calculated by applying personal domestic expenses. As a result, the standard of the estimated unit showed a good ratio of 107% for heavy pruning of street tree pruning compared to the actual construction cost, but light pruning was underestimated with a 59% ratio. Shrub pruning was 82%, weeding was 92%, tree fertilization was 87%, and windbreak wall installation was 91% under-engineered. In addition, it was also confirmed that the watering by sprinkler trucks and chemical spraying were over-designed compared to the actual construction cost at the rates of 118% and 124%, respectively. Due to the specificity of the street trees, the increase in personal expenses and the input cost of equipment, such as road safety controls, were judged to be the main cause of the underestimation of items. Therefore, it is necessary to add items related to street trees and general landscape trees to the landscape maintenance items of the standard of the estimated unit.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.327-335
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• 2018

In order to calculate the quality management cost of construction work, the process must conform to relevant laws and regulations. In details, the cost of the various items such as quality test fee and quality control activity cost are required to be calculated. Regarding the quality management costs, the labor cost is applied to the quality examination fee and the calculation unit quantity in the construction quality management duties. The application of the unit price of the labor cost stipulates that Construction Association of Korea and Korea Engineering & Consulting Association apply the unit price which is surveyed and published. However, in the related laws and regulations, the standard of the quality manager and quality tester is not clear. This accounts for the confusion in the cost of construction management and the cost of labor. In the current law, the allocation standard of quality control personnel is specified according to the size of the construction, but the standard of placement of quality testers is not specified. At the construction site, there is no assignment criteria manpower for quality testers except quality managers, or very little work is being done. The quality control personnel conducts the quality test work to be carried out by the quality tester, and this carrying out heavy work. Therefore, it is difficult to maintain quality control activities. In this study, the labor cost of quality management expenses and the allocation criteria of quality managers and quality testers are established and presented for the purpose of securing the quality of the construction work and preventing the construction work. It is stipulated that the standards of the relevant laws and regulations, which are not clear, should be classified into quality control personnel and quality testers according to the size of the construction. Based on the unit price of Korea Engineering & Consulting Association, the personnel expenses of quality managers and quality testers are proposed to apply the unit price of engineer (professional engineer, specialist, advanced, intermediate, beginner) and skilled technicians (advanced, intermediate, beginner).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.457-468
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• 2011

Recently, the non-vibration mass excavation method is used on sewage pipes and road construction sites in Jeju. However, a construction cost estimation based on the unit quantity does not provide a proper unit price. In this study, a comparison of the productivity of the standard quantity-per-unit costing method and the one of the work crew combination method was made based on the site monitoring of the non-vibration mass excavation method that is used in construction sites near Jeju. For this, data of 35 sites were collected: a regression equation was derived from the 30 data, and verification was carried out through the remaining 5 data. The analysis concluded that a day's workload is $16.43m^3$. In addition, a combination of the equipment considering the site conditions and the amount of labor, which varies with the number of work crew was obtained in order to estimate the construction cost of the work crew combination method. The construction cost was calculated based on the one-day workload ($16.43m^3$) derived from the regression analysis. The cost then was analyzed and compared with the standard quantity-per-unit costing method.

• Journal of Information Technology Services
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• v.16 no.3
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• pp.47-65
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• 2017

The reference guide for the cost of establishing the digital documents has been used as a basis for establishing the budget for the construction of the knowledge information resource. However, due to the abolition of the nominal unit price notification in terms of IT projects, it is necessary to conduct research to convert the standard of the current labor force grade standard to the national incompetency standard (NCS). In this study, we investigate and revise the system and contents of the current knowledge information cost estimation model. In specific, i) we conducted gap analysis of cost estimation model and existing NCS model. As the contents conforming for the construction of the knowledge information resource were not adoptable, we define the description of the construction of the knowledge information resource and to identify the core elements of NCS prior to the improvement of the cost model. ⅱ) then we proposed improve the cost model considering integration with newly proposed NCS model for knowledge information construction job. In order to ensure the validity of the application of NCS development and cost estimation model, the experts reviewed relevant contents and made plans for improvement by using experts from supply and demand groups of various fields of national knowledge informatization projects.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.791-800
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• 2013

Needs for developing a better way of cost estimating process for public construction projects have been widely recognized. Those needs are mainly from the early phases of the project through the construction life cycle due to the its importance to the control process. In contrast to the traditional estimating method based on unit-price references, this research utilized this following process. The first step is analyzing the real cost data from actual cost activities (2000~2010) about the statement of P.S.C(Prestressed Concrete) Box Girder Bridge. The collected data was broken into four categories based on technical construction methods such as I.L.M(Incremental Launching Method), M.S.S(Movable Scaffolding System), F.S.M(Full Staging Method), and F.C.M(Free Cantilever Method). The second, actual design documents including the actual cost estimating documents, drawings and specifications were carefully reviewed to cluster the cost itemized statement from four categories. It was also attempted to seek the proper breakdown of standard works that are responsible for more than 95 percentage in each categories in terms of its cost. The third, this research comes up the index for standard unit materials and unit price of standard work and develops the approximate estimating model applying for the specification(length and breadth of bridges) per square area that the user takes as well as suggests the practical application plan within the original time alloted.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.540-545
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• 2008

The purpose of this study is to suggest problems and improving plan of process of calculating escalation rate of the Historical Cost by price fluctuation. In order to implement this research, we analyzed problems by calculating the rate of price fluctuation with Historical Cost and measurement applying method making on-site with historical cost data were included as samples and suggested improving plan to the adjustment of contract cost. The results of research according to this are same as followings:1) Of all construction details, it is more appropriate to calculate price fluctuation by applying measurement method to the contents of historical cost unit. 2) To avoid confusion in calculating method, it was indicated that amendment in part should be achieved in order to calculate by measuring the part of calculating escalation rate of Historical Cost at related law and regulation.

• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.107-116
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• 2009

As the Fundamentals of Construction Business Act was revised in December 2004 and its implementing ordinances and enforcement regulations were adjusted in June 2005, the screening system of low price subcontracting has been an obligation to the public owners, having brought about arguments for and against since it enacted in 1983. The statutes for low price subcontracting have been reinforced from this year; for example, it underlines to submit to a project and builds an information network of subcontracting works. The system's original intention was that prevents shoddy and fraudulent constructions caused by low price subcontracting and precludes disturbances of fair trade by screening that whether it satisfies the conditions or not in advance. But, the criterion for the existing low price subcontracting has several issues having held up a true mirror to the real situation. It is arguable to discharge an important task with the primary purpose. This dissertation have researched the problem with a deposit of subcontract and the low price subcontracting basic rate are being used by the criteria for deciding whether it is a low price subcontracting or not, so showing the plan of reformation based on the findings, it wishes to contribute toward making the most of the system's essential intent.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.75-76
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• 2020

Use fire resistant construction methods, of which fire resistant boards are used to protect buildings and structures from fire. However, in the case of fire resistant boards, the unit price of the main raw material is high and the cost efficiency is low. There have been studies to apply oyster shells to fire resistant boards to solve these problems. On the other hand, egg shells are also considered to be applicable to fire-resistant boards with components like oyster shells, but there is no case of using egg shells as building materials. Therefore, in this study, we confirmed the physical properties of egg shell powers used as mortar filler and compared them with the fire resistant board flexural strength standard. As a result, it was judged that the powder of egg shells could be used as a building material, because the standards for the flexural strength of fire resistant boards were satisfied except for a part.