• Journal of the Korea Institute of Building Construction
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• v.13 no.4
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• pp.372-381
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• 2013

In the construction industry, a great deal of research has been focused on productivity improvement because a minor change in labor productivity can often make the difference between a profit and a loss. This study shows how productivity measurement methods can be applied in practice, step by step, to analyze and identify potential problems both in productivity and methods performance for masonry work. A work sampling technique was conducted to determine the nature and extent of an observable activity as an aid to measuring overall performance. Also, a method productivity delay model was used to identify non-productivity in individual cycle times. From the work sampling technique, it was found that the masonry crew had a Labor Utilization Factor of 47.1%, and from the videotape analysis, it was found that the material and dumpster location need to be adjusted to reduce the travelling distance. We have found that efforts to improve the productivity of masonry work should be focused almost exclusively on machine and labor delays, based on the result from the method productivity delay model.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.952-959
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• 2022

Active construction work zones will result in longer travel time and/or longer travel distances for road users because of reduced speed limits and/or detours. This results in increased fuel consumption and increased emissions of harmful gases such as Carbon Monoxide (CO), Nitrogen Oxides (NOx), and Sulfur Oxides (SOx), which causes discomfort to the environment and road users around the work zone. The impact of such emissions should be considered while designing work zones or determining the number of days the roadway will be allowed to be closed partially or fully. This study develops a methodology to compute additional road user costs associated with such work zones. To achieve this goal, a) an extensive literature review is conducted, b) a framework to compute emission cost is developed, c) emission rates are computed for all counties (95) of the state of Tennessee, and d) a case study is conducted to demonstrate the use of the framework to estimate the additional impact of emission because of the work zone. For the case study conducted, the emission cost was computed to be $10,653.60 for the duration of the project. State DOTs can account for such road user costs while selecting contractors using A+B bidding. Accounting for such impact of emission will also indicate the agency's willingness to consider sustainability as a part of the business practices.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.3
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• pp.733-742
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• 2013

The Korea has significant tidal current energy resources, but it is so hard to work underwater for tidal turbine installation. Therefore commercial diving work is very important for tidal current generator. Also, Jangjuk channel is vary famous as proper area to generate tidal current energy. Nevertheless, no one is studied about characteristics of commercial diving works with installation of tidal current generator. The purpose of this study is to introduce commercial diving with work types and investigate critical limits of diving working under the conditions, which are working only to minutes at slack tide during the neap tide. As the results, work types are five as like mooring installation, OMAS(Offshore Maintenance Access System), support structure installation, cable and turbine installation. Here, the original construction period is expected about 4 months, but the construction take 18 months to complete. The cause of extends construction period is insufficiency of researching tidal current conditions at the site and ignorance of slack tide which need to secure diving working time. Total diving working times are 110th during 18 months, the highest percentage of diving times is turbine installation about 43.6 %, and cable, mooring installation and support structure construction are 27.3 %, 15.5 %, 13.6 %, respectively. On the basis of this study, estimation of times of commercial diving is possible with work types of tidal current power, and has a significance as basic data to determining construction period.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.483-486
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• 2006

The value engineering(VE) in construction projects is systematic method which improve quality as well as reduction input cost and as construction VE work extends the range of application, the importance is rising. For this reason studies are needed to enforce design value engineering work systemically and effectively. In this study, we analyzed the problem of the present construction VE processing and deduced the model to be most suitable the work efficiency. As suggested model reflects systemically requirement item of owner and user, it will make approaching direction and standard establishment possible. So it will increase the following function analysis in analyzing step and the effectiveness of creating idea and make successful VE result.

• Journal of People, Plants, and Environment
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• v.22 no.5
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• pp.467-480
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• 2019

Standard estimates are the numerical data of a unit quantity required for construction work such as the amount of materials, manpower, and the use of equipment required and are also a basis to calculate construction costs. Unfortunately, standard estimates for construction have also been used for garden construction these days as no standard estimates for garden construction have been developed or documented until now. As a result, many problems have arisen at garden construction sites since landscape construction and garden construction differ in terms of scope, size, design and construction methods. The purpose of this study was to develop standard estimates for garden construction for proper calculation of the cost of garden construction and to ensure gardens are created following appropriate construction processes. In order to develop standard estimates for garden construction, a preliminary survey was conducted on experts to understand current issues at first. After that, a questionnaire survey was done to examine problems of construction processes and ways of improvement, and on-site inspections were conducted utilizing CCTVs at construction sites to identify the actual amount of manpower required on site. Based on the results of the surveys and on-site inspections, a draft version of standard estimates for 5 types of planting work for garden construction was developed. Developing standard estimates for garden construction will serve as a stepping stone for the transparent and proper compensation for garden construction work, which will not only contribute to addressing issues between consumers and construction companies, but also to the stabilization of market economy and job creation.

• KIEAE Journal
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• v.10 no.5
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• pp.165-170
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• 2010

Super high-rise mixed use buildings require a longer period for construction. Especially finishing work takes up about 40% of the whole construction period. Thus, finishing work is becoming an important factor in determining the construction period along with earth work and frame work. As the expected returns added by the reduction of the period and cost in constructing super high-rise mixed use buildings are huge, the expectations are now increasing for the possible gains. In this respect, as the period of finishing work is easier to be shortened than that of frame work, the efforts to acquire the technical knowledge to reduce the finishing work period are now being required. Accordingly, in this study, we aimed at suggesting the basic data for designing an economic plan for finishing-work procedure by analyzing the productivity of each work type of finishing work procedure on the basis of the execution and results of a construction method as a time-flexible finishing work plan. For this, we categorized the work types of finishing work procedure into each work unit and provided a work-system for each of them. Also, with case studies, we calculated the detailed amounts of the work-loads, required materials, productivity, and productivity index of the main work types of finishing work procedure and each of their separate work units as well as analyzed the relationship between the value results to suggest a better way to improve its productivity.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.41-49
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• 2007

GS E&C had developed construction management system, PMS which is based on EVMS in 1997. Recently, TPMS has developed for effective construction management through applying daily schedule management and JIT on materials, labors, equipments focusing field work. TPMS realizes "Shielding" and "Make-Ready Process" which are the main concept of Lean construction. Through this system, it can manage and plan daily field work, support the field work related material, labor, and equipment planning, and minimizes the non-valuable process. This paper introduces the concept of TPMS, and through established system, it can lead the construction culture and raise the competitive power of construction industry

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.131-132
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• 2022

The type and proportion of construction work varies depending on the stage of progress, and the frequency of inspection and defect occurrences are different. If it is determined to be defective after the inspection, a delay may occur, and additional manpower and resources are required. Therefore, it is necessary to prevent these risks by classifying, deriving, and managing key management woks according to the progress. This study aims to contribute to the efficiency of the supervisor's inspection work by identifying the types of construction that should be managed intensively for each construction progress and deriving the time when defects occur frequently in each construction type.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.256-261
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• 2008

The curtain-wall work has been more frequently applied in the construction industry since demand of high-rise buildings has been increased. The curtain-wall work is usually performed with the frame work simultaneously for reducing construction period, but it might be delayed because of several problems caused by interference of process. However, there is not an appropriate tool which can be used by a work manager for adjusting quantity of the construction equipments or the workers when the curtain-wall work was delayed. To resolve this problem a construction simulation anticipating and analyzing potential problems before starting the work can be applied in the curtain wall work. This research suggests a general model for the curtain-wall work by using construction simulation and produces a combination of construction equipments and workers which can estimate optimum work productivity.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.113-122
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• 2009

The domestic construction market started to expand steadily since 1970s. The building market which utilizes a sandwich panel with advantages of economical construction expenses and convenient construction has grown rapidly in recent years. However, the companies which specialize in constructing sandwich panels are relatively small or medium size, compared with other construction companies. As a result, studies on the improvement of productivity have not been conducted sufficiently. In this study, the construction sites of sandwich panel are investigated, and the work processes by each team are analyzed. Additionally, the productivity and the construction cost of each work group are analyzed by constructing a model using the Web-Cyclone. It analyzed sensitivities about change of productivity and work costs following in processing place of the panel which is one of the productivity effect factors, so it assayed the optimized productivity by each work group and work costs. Analysis showed that 30% of productivity has improved compared with the factory processing work group, and analysis of work costs showed that about 15% of work costs was increased. Also sensitivity analysis of opening ratio showed that the work costs optimization will be accomplished when about 20% of opening was processed from the factory.