스마트건설안전 비용의 안전관리계획서 계상 현황 분석을 통한 활성화 방안 연구

원정훈,장남권,유지영,Won, Jeong-Hun,Jang, Nam Gwon,Yu, Ji Young 한국안전학회 2022 한국안전학회지 Vol.37 No.3

This study analyzed the smart construction safety cost included in safety management plans that are approved before construction. Specifically, it refers to the cost incurred in constructing and operating a safety management system using wireless communication and facilities. Based on the obtained statistical results, an activation policy for the inclusion of the smart construction safety cost in building safety management plans was proposed. The smart construction safety cost must be included in the safety management cost; notably, this is mandated by the Construction Technology Promotion Act. However, there are some problems with the inclusion of smart construction safety costs. To analyze the problems encountered when calculating the smart construction safety cost and including it in safety management plans, in this study, statistical analysis was performed using the data of 1,334 safety management plans received at the Construction Safety Management Integrated Information (CSI) from June to August 2021. The results show that only 50.7% of the safety management plans included the smart construction safety cost although the current law mandates 100% inclusion of these costs. Thus, it is apparent that the smart construction safety costs are only included in a low proportion of sites. In addition, the calculated smart construction safety costs were shown to have a small correlation with the construction cost; moreover, they appeared to be distributed at a constant cost level. In this context, it is believed that perfunctory cost calculations were performed at most sites since the effect of the construction cost on the smart construction safety cost was negligible. Therefore, it is necessary to improve the inclusion of smart construction safety costs by strengthening the authorization process of the approval institute of safety management plans. In addition, institutional support, such as guidelines that promote the calculation and inclusion of appropriate smart construction safety costs according to the characteristics of sites, are needed.

건설업 원가계산 및 관리의 문제점과 개선방향

윤종철,한종수,이상철 한국회계학회 2018 회계저널 Vol.27 No.3

건설업은 개별 건설현장을 원가대상으로 설정하여 원가를 집계하고 관리하는 개별원가계산시스템을 적용하고 있다. 건설원가는 수급자인 건설업자가 건설공사의 전부 또는 일부를 다시 도급하는 하도급 구조를 가지고 있기 때문에, 일반 제조업의 재료비, 노무비 및경비의 3가지 원가요소 이외에 외주비라는 항목을 추가로 구분한다. 건설원가요소 가운데외주비가 차지하는 비중이 가장 높으며, 그 다음으로 재료비, 현장경비 및 노무비의 순으로비중이 낮아지는 것으로 나타났다. 건설원가에서 차지하는 비중이 가장 낮은 노무비는 건설규모가 커질수록 비중은 더욱 낮아지는 것으로 나타났다. 한편 건설원가를 건설현장에집계하기 위해 건설원가를 직접건설원가와 간접건설원가로 구분한 후, 직접건설원가는 건설현장에 직접 추적하는 반면 간접건설원가는 3단계의 배부과정을 거쳐 건설현장에 집계한다. 건설업은 공사기간이 장기여서 건설환경의 변화에 따라 원가발생의 변동성이 커질 수 있고원가대상인 건설현장의 여건과 시공조건의 제약에 따라 투입되는 원가요소가 달라지기 때문에, 일반제조업에 비해 원가관리가 어렵다. 그리고 하도급으로 인해 발생하는 외주비가건설원가의 절반을 넘는 비중을 차지하고 있기 때문에, 하수급인의 원가관리 역량이 건설현장의 원가관리에 직접적인 영향을 미칠 수 있다. 이러한 상황에서 한국 건설업은 외부이해관계자를 위한 재무보고에 초점을 맞추어 원가를 계산해왔으며, 건설기업의 자원을 효율적으로 배분하기 위한 관리적인 목적에서 원가계산 및 관리가 이루어지지 못했다. 간접건설원가 비중이 높아짐에도 불구하고 간접건설원가를 직접건설원가에 비례하여 건설현장에배부하기 때문에, 건설현장에 대한 원가계산의 왜곡은 물론 정확한 수익성을 분석하지 못하는 한계가 발생한다. 건설업의 특성에 의해 표준설정과 통제가 어렵고, 외주비에 대한 체계적인 관리가 이루어지고 있지 못하며, 건설현장 및 하수급인의 원가마인드가 미흡하며, 원가계산 및 관리를 위한 조직과 전문인력이 부족하고, 전략적 관점에서 건설원가를 관리하지 못하는 것도 문제점으로 지적할 수 있다. 이러한 문제점을 개선하기 위해서는 정확한 건설원가를 계산할 수 있는 시스템을 갖추는것이 중요하다. 추적이 어렵거나 추적으로 인한 효익이 비용보다 낮은 간접건설원가를 발생시키는 활동을 분석하여, 활동을 매개로 건설원가를 건설현장에 추적하는 활동기준원가계산방법을 적용할 필요가 있다. 시공 및 이후단계에서 전체수명주기원가의 대부분이 발생하지만 시공이전 단계에서 대부분의 원가가 확정되기 때문에, 시공이전 단계인 구상 및 설계단계에서 비효율을 제거할 수 있는 노력과 역량을 개발할 필요가 있다. 건설현장 구성원들이 원가마인드를 갖추고 원가관리에 적극적으로 참여하고, 하수급인의 원가관리 역량을강화하며 협력할 필요가 있다. 가치공학과 수명주기원가계산 이외에 활동기준원가관리, 목표원가계산 및 품질원가계산과 같은 전략적 원가관리기법을 이용하여 경쟁우위를 얻기 위한 장기적인 원가관리 노력을 기울여야 한다. 건설원가정보시스템을 구축하여 건설원가관리를 위한 의사결정에 필요한 정보를 제공할 수 있어야 하며, 건설원가관리를 위한 본사전담부서와 건설현장의 원가관리를 위한 조직을 만들고 전문인력을 보강할 ... Job-order costing is used in the construction industry to determine costs for each individual construction project. One thing peculiar is that, in addition to the three basic elements of manufacturing costs such as materials, labor, and overhead costs, subcontracting costs commonly incur in almost all construction projects. The subcontracting costs are actually the largest element of construction costs, followed by materials, overhead, and labor costs. The proportion of labor costs decreases as the project size increases. The construction costs are also classified into direct and indirect costs. Direct costs are traced directly to each specific construction project, whereas indirect costs are allocated using the three-step procedure. Cost management in the construction industry is more complicated, comparing to other industries, because there is a high volatility in costs due to a long-term nature of construction. It is also because the combination of cost elements differs depending upon the conditions of construction sites and constraints on construction contracts. Moreover, since subcontracting costs account for more than half of construction costs, subcontractors’ ability to manage costs has direct effects on cost management. Interestingly, in Korea, construction costs are computed for external reporting purpose rather than for management purpose. Indirect construction costs, even though they have been constantly increased, are allocated to each construction project in proportion to direct construction costs. It results in distortions in cost estimation and/or profitability analysis. Other factors that may cause poor cost management include: difficulties in setting cost standards, non-systematic management of subcontracting costs, lack of subcontractors’ awareness of cost management, insufficient man power for effective management of costs, and ineffective use of strategic cost management system. To address these problems, construction companies need a system that enables them to find accurate construction costs such as Activity-Based Costing (hereafter, ABC). ABC is a method to identify activities incurring indirect costs which are hard to be traced. It is also necessary to make efforts to reduce inefficiency at the pre-construction designing stage, where most of the life-cycle costs are determined. All members of the construction project should also be involved in managing costs. Contractors should cope with their subcontractors in improving subcontractors’ skills of cost management. Long-term efforts to manage costs are especially required to achieve competitive advantages; applying strategic cost management methods such as ABC, target costing, and quality costing. A construction cost information system is also needed to provide information for decision-making. Finally, it is necessary to establish cost management departments at both the head office and construction sites, and to address issues through continuous communication between the head office and construction sites.

공공공사비 산정의 공정성과 투명성 제고 방안 연구: 추정가격과 예정가격을 중심으로

권세훈,신만중 한국부동산법학회 2019 不動産法學 Vol.23 No.2

Although the profitability of domestic public construction work has deteriorated every year due to the public construction cost policy in terms of the reduction of SOC budget and efficiency of budget reduction, the government does not try to improve the system for calculating the construction cost. This study compares and evaluates the domestic and the US in the estimation of public construction cost and suggests institutional improvement methods to improve the fairness and transparency of public construction cost estimation by analyzing case studies of underpricing of construction cost and systematic problems of costing estimation process. First, in order to estimate the fair construction cost, it is necessary to enact the regulation of the construction cost, to specify the reasons when cutting, and to introduce the screening system of the construction cost. In terms of the flexibility of the budget operation system, it proposes a contract considering the balance of the winning bid, an adjustment of contract amount after contingency, and a value engineering after approximate contract. Second, in order to estimate the transparent construction cost, it proposes to disclose all calculation data of the construction cost, and proposes the real name system for those who estimate the construction cost. Third, in order to remedy the unfair reduction of the construction cost, it proposes the adjustment of contract amount due to the design change or other changes in the contract contents and the appeal for government dispute mediation. In order to secure its effectiveness, it proposes penalties for those who estimate the construction cost. Finally, it proposes to secure the expertise of those who estimate the construction cost and to estimate the construction cost by a qualified person such as construction cost manager, cost analyzer, and so on. 정부의 SOC 예산 감소와 예산절감이라는 효율성 측면의 공사비 정책으로 국내 공공공사의 수익성은 매년 악화되고 있으나, 정부의 공사비 과소산정에 대한 제도개선은 미진한 실정이다. 이에 본 연구는 공공공사비 산정과 관련하여 국내와 미국을 비교·고찰하고 공사비 과소산정 사례조사와 공사비 산정과정의 제도적 문제점 분석을 통하여 공공공사비 산정의 공정성과 투명성 제고를 위한 제도적 개선방안을 제시하고자 한다. 첫 번째, 발주기관의 공정한 공사비 산정을 위해 공사비 산정규정을 강행법규화 하고 삭감할 때에는 그 조정사유를 명시하도록 하며, 공사비 적정성 심사제도를 도입한다. 예산운영제도의 유연성 측면에서 낙찰잔액을 고려한 공사 발주와 예비비 편성 후 계약금액 조정 그리고 개산계약 후 설계의 경제성 검토를 통한 변경계약을 제안한다. 두 번째, 발주기관의 투명한 공사비 산정을 위해 공사비 세부 산정근거 일체를 공개하고 공사비 산정주체 전체에 대하여 실명제를 제안한다. 세 번째, 공사비 부당삭감에 대한 구제방안으로 설계변경 또는 기타 계약내용의 변경으로 인한 계약금액 조정과 국가계약분쟁조정을 위한 이의신청을 제안하며, 그 실효성을 확보하기 위하여 부당삭감 시 공사비 산정주체에 대한 벌칙을 제안한다. 마지막으로 공사비 산정주체에 대한 전문성 확보와 건설원가관리사, 원가분석사 등 전문자격을 갖춘 자가 공사비를 산정하도록 제안한다.

개략공사비 산출을 위한 공사비 지수 연구 : 1970-1999

남송현,박형근 대한토목학회 2020 대한토목학회논문집 Vol.40 No.5

A significant factor in construction work is cost. At early- and advanced-stage design, costs should be calculated to derive realistic cost estimates according to unit price calculation. Based on these estimates, the economic feasibility of construction work is assessed, and whether to proceed is determined. Through the Korea Institute of Civil Engineering and Building Technology, the construction cost index has been calculated by indirect methods after both the producer price index and construction market labor have been reprocessed to easily adjust the price changes of construction costs in Korea, and the Institute has announced it since 2004. As of January 2000, however, the construction cost index was released, and this has a time constraint on the correction and use of past construction cost data to the present moment. Variables were calculated to compute a rough construction cost that utilized past construction costs through surveys of the producer price index and the construction market labor force consisting of the construction cost index. After significant independent variables among the many variables were selected through correlation analysis, the construction cost indexfrom 1970 to 1999 was calculated and presented through multiple regression analysis. This study therefore has prominent significance in terms of proposing a method of calculating rough construction costs that utilize construction costs that pre-date the 2000s 건설공사를 진행하는데 있어 중요한 요소 중 하나는 가격이다. 정확한 예정가격을 산정하기 위해 기본 및 세부 설계 단계에는 단가산출에 따라 가격을 산정하고 이를 토대로 건설공사의 경제성을 평가하고 진행여부를 판단한다. 국내에서는 건설공사비 가격변동을 손쉽게 조정할 수 있도록 건설연구원을 통해 건설공사비 지수를 산정하여 2004년부터 발표하고 있다. 그러나 2000년도 1월부터 지수가 산정되어 지수 발표 이전 시기의 건설공사비 자료를 사용하지 못하는 실정이다. 과거 공사비를 이용한 개략공사비 산출을 위해 건설공사비 지수를 구성하는 생산자 물가지수와 건설업 시중노임 조사를 통해 변인들을 산정하였다. 다수의 변인 중 상관분석을 통해 유의한 독립변수를 선정 후 다중회귀분석을 통해 1970년도부터 1999년까지의 건설공사비 지수를 산정하여 제시하였다. 본 연구는 2000년대 이전의 과거 공사비를 활용한 개략공사비 산정방법을 제시한 부분에 중요한 의의를 가진다.

Approximate Cost Estimating Model of Eco-type Trade for River Facility Construction Using Case-Based Reasoning and Genetic Algorithms

이시욱,진영민,우성권,신도형 대한토목학회 2013 KSCE Journal of Civil Engineering Vol.17 No.2

Cost estimation in the construction industry is a critical process for the successful execution of construction. In particular, the total cost for a construction project is determined at the planning stage, and its estimation is very important because the decision making of the construction project owner regarding the project size, budget, and construction time depends on the total cost estimation. However, research concerned with the cost estimation for river facility construction has focused on research applicable in the early design stages rather than at the planning stage, which is the initial stage of a construction project. In addition, mainstream research has concentrated on the development of models centered on the estimation techniques being used currently in actual design engineering fields. For this reason, this study has developed an approximate construction cost estimating model for the eco-type river facility construction trade by applying Case-Based Reasoning (CBR) and Genetic Algorithms (GAs), which can be used at the planning stage. In order to develop the model, historical data was collected and analyzed; in order to overcome the limitations of the data collection, virtual data were also created and used. The model was developed in such a manner that it can estimate the construction cost with only eight and eleven attributes for the two eco-type trades used in the model, which can be applied at the planning stage. The results of the verification of the proposed model indicate that the model is satisfactory when applied in the approximate cost estimation of eco-type trade for river facility construction at the planning stage. It is expected that the proposed model will be applied easily and conveniently to the estimation of the approximate construction cost of eco-type trade for river facility construction at the planning stage.

소규모 시공현장 적정공사비 확보를 위한 원가기준 마련 연구

오재훈 ( Oh Jae-hoon ),안방율 ( An Bang-yul ) 한국건축시공학회 2023 한국건축시공학회 학술발표대회 논문집 Vol.23 No.1

In construction sites, small-scale construction quantities or limited work hours below the daily work volume may occur due to on-site conditions. For small-scale quantities, the input of equipment and labor is designed based on an hourly basis in the invoice, resulting in a difference from the actual cost. In this study, we aim to explore solutions from the perspective of construction cost standards to secure appropriate construction costs for small-scale and time-limited construction sites. Firstly, to preserve the basic construction costs on-site, we established standards where half the cost would be charged for construction quantities below four hours and a full day’s cost would be designed for construction quantities between four to eight hours. Additionally, realistic construction cost calculation standards are expected to be provided by realizing a surcharge rate for work hour limitations to secure appropriate construction costs.

머신러닝을 활용한 계획단계 도로공사 공사비용 추정 모델 개발

김제원,김준수 한국도로학회 2023 한국도로학회논문집 Vol.25 No.6

PURPOSES : Construction cost estimates are important information for business feasibility analysis in the planning stage of road construction projects. The quality of current construction cost estimates are highly dependent on the expert's personal experience and skills to estimate the arithmetic average construction cost based on past cases, which makes construction cost estimates subjective and unreliable. An objective approach in construction cost estimation shall be developed with the use of machine learning. In this study, past cases of road projects were analyzed and a machine learning model was developed to produce a more accurate and time-efficient construction cost estimate in teh planning stage. METHODS : After conducting case analysis of 100 road construction, a database was constructed including the road construction's details, drawings, and completion reports. To improve the construction cost estimation, Mallow's Cp. BIC, Adjusted R methodology was applied to find the optimal variables. Consequently, a plannigs-stage road construction cost estimation model was developed by applying multiple regression analysis, regression tree, case-based inference model, and artificial neural network (ANN, DNN). RESULTS : The construction cost estimation model showed excellent prediction performance despite an insufficient amount of learning data. Ten cases were randomly selected from the data base and each developed machine learning model was applied to the selected cases to calculate for the error rate, which should be less than 30% to be considered as acceptable according to American Estimating Association. As a result of the analysis, the error rates of all developed machine learning models were found to be acceptable with values rangine from 17.3% to 26.0%. Among the developed models, the ANN model yielded the least error rate. CONCLUSIONS : The results of this study can help raise awareness of the importance of building a systematic database in the construction industry, which is disadvantageous in machine learning and artificial intelligence development. In addition, it is believed that it can provide basic data for research to determine the feasibility of construction projects that require a large budget, such as road projects.

택지개발사업에 의한 근린공원의 개발비용분석

林元炫 경주대학교 건설환경연구소 2004 建設環境論叢 Vol.- No.6

In general, neighborhood parks resulting from housing estate development project are preserved natural forests within parks created on a new ground that is artificially laid through earth works. How a park has been developed influences the characteristics of the park such as land use, park facilities, planted trees and construction costs. Thus the present study attempted to compare and analyze these characteristics and propose rational and efficient directions and ideal options for park planning and development in the future. In addition, it was focused on defining reasonable processes of introducing preserved neighborhood parks and created ones and suggesting methods for proper construction cost estimation, optimal land use planning, right facility deployment, etc. Subjects of the research were eight created neighborhood parks and seven preserved ones, which were within sites in Daegu or Gyeongsangbuk-do where housing estate development had been completed or was in progress. These parks were analyzed in terms of the reality of development by type, construction cost, and unit construction cost efficiency chronically before and after the work. Conclusions drawn from the analysis are as follows. 1. When comparing the number of changes in design for the whole landscaping in sites with that for the neighborhood park, the ratios are between 50-87 % except Daegu Dongho Site and Daegu Seongseo the 3rd Neighborhood as well as Gyeongsan Sadong Site, Andong Jeongsang Site and Kimcheon Bugok Site, in which the number of changes in design was three or less. 2. According to the result of calculating the construction cost per ㎡ by dividing the park construction cost into the area of the park and comparing cost efficiency, the cost per unit area in created parks is 4.1 times higher than that of preserved parks. 3. As for construction cost per ㎡ in individual sites in Daegu and Gyeongsang buk-do, created parks cost between 21,000-50,000 won per ㎡ except that in Daegu Chilgok the 2nd Site, the unit cost of which is beyond the deviation range, and preserved parks cost between 1,300-3,800 won per ㎡ except those in Daegu Seongseo 4 and 5 neighborhood, the unit cost of which is beyond the deviation range. Thus the unit construction cost of created parks was 13-15 times higher than that of preserved parks. In comparison between the two types of parks in the whole country as well, the unit construction costs of created parks ranges between 24,100-31,800 won while that of preserved parks between 3,600-9,300 won. Thus the former is 3.4-6.75 times higher than the latter. The results of this study have been presented above as basic materials for planning and creating neighborhood parks in housing estate development site and forecasting proper construction cost by the work item, and by the unit work cost of parks as well as key indexes for optimal land use planning and facility deployment. Considering the results, it is considered desirable to build preserved neighborhood parks than created ones, and to include plans to build sustainable parks using natural forests in planning land use for housing estate development.

소규모 건축공사의 적정 실적공사비 단가보정 모델 개발

김강식,현창택,홍태훈,조성민,문현석 한국건축시공학회 2010 한국건축시공학회지 Vol.10 No.1

Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget. 정부는 2004년부터 원가산정체계를 실적공사비 중심으로 전환하였다. 이러한 실적공사비는 계약단가를 기준으로 산정되며,현재 10억원 이상의 공공 건설공사에 적용되고 있다. 그러나 대형공사 위주의 평균단가로 구성되어 있는 실적공사비를 10억원미만의 소규모 건축공사에 직접적으로 반영하게 됨으로써 소규모 건축공사의 실행금액이 계약금액 이상으로 증가되는 경우가빈번히 발생하고 있다. 뿐만 아니라, 이에 따른 영업이익의 감소로 기업운영 및 생산성 등에 악영향을 미치는 등과 같은 여러문제들이 야기되고 있다. 따라서 10억원 미만의 소규모 건축공사에 실적공사비를 적용하기 위해서는 사업의 규모 등을 반영할수 있는 단가보정 방안이 있어야 한다. 이에 본 연구에서는 실적공사비를 10억원 미만의 소규모 건축공사에 적용하는데 발생할수 있는 단가적용의 문제를 해결하기 위하여 실적단가를 보정할 수 있는 실적공사비 단가보정 모델을 개발하였다. 이 모델은소규모 건축공사의 생산성과 적정한 이윤을 책정하는데 도움을 줄 수 있으며, 소규모 건설업체의 경영이 악화되는 것을 방지할수 있을 것으로 판단된다. 그리고 발주처는 예산편성 시 현실성 있는 공사비를 확보할 수 있을 것으로 기대된다.

공적개발원조(ODA) 건축사업의 타당성 조사단계에서의 공사비 산정방법에 관한 연구: 의료시설을 중심으로

김인경,박준 국제개발협력학회 2022 국제개발협력연구 Vol.14 No.1

Purpose: This study aims to extract problems in the process of construction cost estimation in the feasibility study of medical facilities in ODA which increases in the actual execution phase. Originality: This study contributes to the improvement of the efficiency of the project in the health sector ODA by analyzing the issues of cost estimation in the feasibility study with empirical data. Methodology: The construction cost estimation method and construction cost affecting factors are drawn by analyzing the Contract Rules and Guideline for overseas construction estimation. Six feasibility studies are selected for comparative analysis. The analysis on the previously performed six feasibility studies for medical facilities adopts the factors to find the limitation and improvement plan of the cost estimation method. Result: The review of six cases of feasibility study in this study revealed the followings. First, not all the cases have the common items for costing. Second, all the cases used the construction cost of existing buildings. Third, only two cases adopted local labor costs. Four, no case adopted infrastructure cost in the project site nor equipment cost. Conclusions and Implication: Construction cost estimation in feasibility study of health facilities in ODA projects needs standardized common items including infrastructure cost in the project site, equipment cost, and local labor. Detailed guidelines for cost estimation in the feasibility study in ODA can secure greater credibility by reducing the gap with actual construction cost with EDCF.