• Korean Journal of Construction Engineering and Management
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• 제8권1호
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• pp.57-65
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• 2007

Rebar work is a labor intensive operation, and with labor shortage and high-wage era, the cost is rising, so re-bar manufacturing system in plant is adapted. However there remains a lot of problems. Although manufacturing system in plant, which greatly effects the building's safety, endurance, and construction time, is an important phase in construction, it holds serious problem of quality and productivity deterioration due to its characteristic of intensive-labor and maintaining of old work methods resulting in poor management, and costs increase. Therefor in this study to investigate current situation and problems of rebar work in plant and to find methods of betterment, a survey was conducted to factory engineers in 18 companies.

• Korean Business Review
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• 제19권1호
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• pp.25-34
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• 2006

This research executed research that analyze construction cost and profitability through construction example of direction and subcontracting construction based on common private construction less than 3 billion. The results of this research, is summarized as follows. (1) Analyzed profitability about construction gross and operating profit of direction and subcontracting construction. The construction gross profit rate is 15.2% direction construction, subcontracting construction was analyzed by 1.3% high by 16.5% subcontracting construction, and the operating profit rate is 9.4% direction construction, subcontracting construction was construed by 2.3% high by 11.7% subcontracting construction. (2) Analyzed profitability about operating profit before and after deduction of 4 insurance cost of direction construction. The direction construction operating profit rate is 9.4% before deduction of 4 insurance cost, after deduction was construed that is 7.3% and operating profit rate difference after and before deduction was construed that is 2.1%. Therefore, subcontracting construction (operating profit rate 11.7%) was analyzed that last operating profitability after 4 insurance cost deduction produces more 4.4% about direction construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.579-583
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• 2004

A new and extendable highway should be planned and budgeted by estimating the total construction cost on the basis of the precise cost data. However, the demolition or disjointing cost could not reflect construction site condition sufficiently because it was simply estimated by multiplying the highway structure installation cost by the regular ratio($10\~70\%$) specified in the Korea Standard Estimate. The regular ratio for estimating of demolition and disjointing cost was calculated by not actual construction cost data but subjective experiences of field manager. Therefore, the reliance of the estimated demolition or disjointing cost has been declined. The primary objective of this study is to purpose the standard for estimating proper demolition or disjointing cost of relevant items through various site analysis and survey, and to investigate on the propriety of ratio-unit price method for estimating demolition and disjointing cost.

• Korean Journal of Construction Engineering and Management
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• 제12권6호
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• pp.3-13
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• 2011

The construction industry is still the most risky industry and labor accident is a significant management factor on construction site. Safety management has been studied for improving the safety performance on construction sites. However, Almost all of them have been considered on the site safety management for the contractors and evaluation of accident rate. To resolve the limitation of current research, this study is focused on considering accident result and effort by performing the evaluation of safety level of the head office and site in construction companies. By studying the research about a safety management and interviewing with specialists in safety management, 7 items were selected and weighted based on the KOSHA18001 List. Consequently, The checklist was developed to evaluate safety performance management in construction company and Safety Management Index was suggested to coordinate 1) the score of results in accident rate and 2) the effort to evaluate a safety performance management. Safety Management Index is more helpful to evaluate the safety management results and effort. As a result of considering the score of the accident rate and the safety performance management, the outcome of prequalification was changed. Using this index, contractors will attempt to prevent accidents and owners will be able to discriminate individual differences in bidding process.

• Journal of the Society of Disaster Information
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• 제19권1호
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• pp.1-9
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• 2023

In order to carry out construction work, it is urgent to introduce a proper wage system so that the cost burden of projects that have been won due to bleeding competition among original government buildings based on low-priced bids can be transferred to subcontractors. Purpose: Construction with illegal multi-level industrial structure needs to improve the wage reduction environment leading to order (100%) → original contractor (80%) → subcontractor (65%) → load contractor (65%) and aims to ensure wages for end workers. Method: Investigate the current status of labor cost appropriate payment plan in the construction industry, and investigate the case of the appropriate wage system (P.W) in the United States. In addition, the effect and direction of the appropriate wage system are presented. Result: Individual minimum wage security was also mentioned in the Constitution, and many researchers suggested that only the introduction of an appropriate wage system could solve the problem of reducing worker labor and ensure quality and safety. Conclusion: The proper wage system in the construction industry will block illegal multi-level and illegal foreign work, improve the labor environment in the construction market, create an influx of young workers, and have a significant impact on the construction industry's competitive structure, safety, and quality.

• Journal of Korean Society of Forest Science
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• 제112권2호
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• pp.217-229
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• 2023

Forest projects often apply construction industry labor rates, without considering the demanding work conditions and labor intensity unique to forest operations, resulting in workplace issues. This study aims to analyze forest operations' characteristics and wage survey methods in other fields to establish a framework for surveying the wages of forest workers. The developed framework was tested through direct surveys conducted with all forest operation companies. Survey items included actual wages by occupation, identification and removal of outliers using quartile deviation, and occupation-based wage calculation. Results revealed that the appropriate wages for 2022 were as follows: KRW 163,376 for general workers, KRW 221,407 for special workers, KRW 250,045 for work leaders, and KRW 239,863 for wood cutters. These figures were 16.27% higher than those derived from the standard construction wage survey. The developed framework was validated by comparing the appropriate wages with both the standard construction wage survey and the forestry workers' wage. The results indicated that the wages calculated using the developed framework were 4.5% more similar to the forestry workers' wage compared with those from the standard construction wage survey. Consequently, the standard construction wage survey was deemed unsuitable for forest projects. To ensure efficient forest operations, it is imperative to conduct wage surveys using the developed framework over multiple years to accumulate sufficient data.

• Korean Journal of Construction Engineering and Management
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• 제23권6호
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• pp.89-100
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• 2022

The development of the Construction Production Rates System for appropriate construction cost calculation has recently come to the fore as a means of invigorating OSC based PC structure which currently needs institutional frameworks. PC structure based construction expenses consist of the factory-built assembly, transportation and on-site installation. Recently, in the field of transportation and site installation, research on product structure development is being conducted, such as presenting the standard product calculation system reflecting the results of field survey for each subsidiary materials (Lee et al., 2021). On the other hand, there is no ongoing research on estimating construction expenses of Factory-built assembly. This study suggests Construction Production Rates System which can be used for PC subsidiary materials based Factory-built assembly cost estimations. For the research, work types for the construction procedures have been categorized, and the standard input manpower suitable for the corresponding work characteristics has been derived from analyzing the associated Construction Standard Production Rates for each work type. Also, as the research referred PC subsidiary materials (such as columns, beams, walls, and slab, as well as on-site installation) and the standard number of workforce based on work types, one can calculate direct labor cost, using what the research shows. In addition, it suggests that the size of individual subsidiary materials be the extra cost factor, by using the characteristics that productivity changes depending on the size(m³) of subsidiary materials. It is expected that the research can contribute to objectively verifying factory-built assembly cost through of PC structure, which currently relies on estimates.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2002년도 학술대회지
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• pp.35-41
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• 2002

This research introduces the development of a project-level cash flow forecasting model in construction stage based on the planned earned value and the cost from a general contractors view on a jobsite. Most previous models have been developed to assist contractors in their pre-tendering or planning stage cash flow forecasts. The critical key to cash flow forecasting at the project level is how to build a cash-out model. The basic concept is to use moving weights of cost categories in a budget over project duration. The cost categories are classified to compile resources with almost the same time lags that are based on contracting payment conditions and credit times given by suppliers or venders. For cash-in, net planned monthly-earned values are simply transferred to the cash-in forecast, to be applied there with billing time and retention money. Validation of the model involves applying data from on-going 4 projects in progress for 12 months. Based on the results of the comparative analyses through the simulation of the proposed model and the existing models, the proposed model is more accurate, flexible and simpler than traditional models to the employee of construction jobsite who is not oriented financial knowledge.

• Korean Journal of Construction Engineering and Management
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• 제21권3호
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• pp.39-47
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• 2020

There are two kinds of cost estimate system in construction in china. Quota valuation model is a traditional cost estimate system under the unity of quantity and price, which is easier and has been used for decades. But the Quota valuation model becomes increasingly unsuited to the needs of society with the development of market economy. To meet the needs of China's market economy development and construction works in the field of international cooperation, the Bill of Quantities valuation model was introduced in 2003. However, there are still many shortcomings and deficiencies in the course of implementation of Bill of Quantities valuation model. In addition, interest in the Chinese construction market continues to increase in Korea due to the recent new North Korean policy and China's the Belt and Road policy. This paper aims to examine the cost estimate system of public construction works in China, and to provide basic data for deriving future improvement plans by comparing and analyzing it with standard cost estimate system in Korea.

• Proceedings of the Korean Institute of Building Construction Conference
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.141-142
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• 2012

Estimating the productivity of labor has relied on the experience and intuition of an estimator, or productivity data, such as standard in practical estimation. However, when new technologies and new construction methods employed in the construction industry, Dependence of a quantity surveyor's intuition is increased. This is because of the lack of a systematic methodology which models, estimates, and measures the labor productivity, Due to the historical productivity data is unavailable. Even thought project history data contains information that is important to predict the performance of a project, It can not provide valuable information to model, estimate, and measure the labor productivity. This is because 1) the absence of the productivity measurement system with consistency, 2) the difficulty of reusability of historical data collected. Therefor, this study suggests a methodology which build a productivity model by measuring the productivity of labor and collecting the historical data systematically. In addition, this methology is applied to develop a productivity model of shop-drawing and manufacturing process using descrete event simulation.