• International conference on construction engineering and project management
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• 2015.10a
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• pp.612-613
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• 2015

As a construction project is recently becoming large-scaled and complex, construction process plan and management for successful performance of a construction project has become more important. Especially a reasonable estimation plan of activity duration is required because the activity duration is directly related to the determination of the entire project duration and budget. However, the activity duration is used to estimate by the experience of a construction manager and past construction records. Furthermore, the prediction of activity duration is more difficult because there is some uncertainty caused by various influencing factors in a construction project. This study suggests an estimation model of construction activity duration using neural network theory for a more systematic and objective estimation of each activity duration. Because suggested model estimates the activity duration by a reasonable schedule plan, it is expected to reduce the error between planning duration and actual duration in a construction project. And it can be a more systematic estimation method of activity duration comparing to the estimation method by experience of project manager.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.902-907
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• 2005

This study was undertaken to develop a comprehensive scheduling method which applied the core concept(DBR) of TOC to PERT, and to combine Monte Carlo Simulation to revise the uncertainties of activities then to eliminate project duration uncertainty. Most of the project duration overlooks the fact that in spite of minimizing the project duration, the uncertainty of constrained resources still puts the reliability of project duration in jeopardy. For the contractor, however, the most important thing is to comply the project scheduling with the planning to reduce the uncertainty of the project activities, operational interaction and project duration. In order to demonstrate that the model can be used in construction project, the scheduling of a steel-structure project was used as a case study to verify the validity of this model.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.137-149
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• 2005

This study proposes a framework enhancing the accuracy of estimation for project duration by combining linear Bayesian updating scheme with the learning curve effect. Activities in a particular project might share resources in various forms and might be affected by risk factors such as weather Statistical dependence stemming from such resource or risk sharing might help us learn about the duration of upcoming activities in the Bayesian model. We illustrate, using a Monte Carlo simulation, that for partially repetitive projects a higher degree of statistical dependence among activity duration results in more variation in estimating the project duration in total, although more accurate forecasting Is achievable for the duration of an individual activity.

• Architectural research
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• v.14 no.3
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• pp.109-116
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• 2012

In order to shorten construction duration in high-rise project, construction company tried to make various system method toward simplifying construction method and shortening construction duration. Though high-rise tower-type residential project are growing, there are few case study. Then, the data for preliminary schedule planning in high-rise tower-type residential project are rare. This purpose of research shows construction method in structural work in high-rise tower-type residential project, suggests schedule planning in structural work through case studies. The structural work in high-rise tower-type residential project was divided 1) completion of form in lower part and 2) the typical floor under penthouse. The statistical analysis were done in two parts, the data from analysis were used in simulation. Finally, researcher confirmed the difference between real construction duration and the figure from simulation. The results shows that the more construction duration is long, the less ACS's cost is low. It means the effectiveness is increasing in ACS, if the floor number is high.

• Land and Housing Review
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• v.2 no.4
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• pp.355-365
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• 2011

Construction duration is very important as a factor which comprises three axises of construction management with quality and cost in construction project. In general project condition, construction duration is optimized while minimizing construction cost and securing required quality. However, in case of insufficient project time duration or delayed projects, project progress management is different from those of normal projects. These project areas need solutions to complete work within a given completion day. To time shortening the current duration of each typical floor of structural framework in apartment construction is investigated, and a basic time schedule planning for typical floor of structural framework in normal projects is planned. This study proposed 3 ways for time shortening of urgent project or insufficient construction duration project. Also, This study proposed detailed time shortening method and technical solution conditions while time is shortened.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.747-753
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• 2009

Planning the construction for a system of bored piles in building foundation engineering is (1) to predict the time duration required to complete all the bored piles with due consideration of relevant engineering factors and site constraints; then (2) to predict the total project time generally by aggregating the predicted working duration for construction of each bored pile. The duration for construction of an individual bored pile results from analyzing various working sequences and different activity duration (such as predrilling, excavation, steelfixing, air-lifting, and concreting, etc.), which is informed by experiences and site records of previous projects. However, determining the project duration for constructing many bored piles on one site is much more complicated than adding up the time duration for individual piles. In practice, project schedules are often found to be unrealistic and incorrect during the construction stage. This is because construction planning is not based on a exhaustive and comprehensive evaluation of site factors, such as site layout plan, site constraints, quality control, environmental control, safety control and logical relationships between different trades. In this paper, we identify those factors based on a foundation engineering site in Hong Kong with ninety-seven bored piles and address their effects on uncertainties in activity time and project time.

• Journal of Information Technology Services
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• v.7 no.2
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• pp.95-111
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• 2008

The objective of this study is to suggest the effects of the fit between project managers' competency and leadership style on the performance of IT projects. Also, this study examine that the project duration among the project's characteristics moderates the impact of the managers' competency and leadership style on the performance of IT projects. As the results of analysis, we found that the participative leadership and the supportive leadership of project manager is affected by the human and the conceptual skills, and the directive-achievement leadership is affected by the technical skills positively. The project duration moderates the impact of the fit between the participative leadership and the technical skills. and the fit between the directive-achievement leadership and the technical and the human skills positively.

• Journal of Construction Engineering and Project Management
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• v.4 no.4
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• pp.33-40
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• 2014

Maximizing the profitability and minimizing the duration of construction projects in extreme weather regions is a challenging objective that is essential for project success. An optimization model is presented herein for the time-profit trade-off analysis of construction projects under extreme weather conditions. The model generates optimal/near optimal schedules that maximize profit and minimize the duration of construction projects in extreme weather regions. The computations in the model are organized into: (1) a scheduling module that develops practical schedules for construction projects, (2) a profit module that computes project costs (direct, indirect, and total) and project profit, and (3) a multi-objective module that determines optimal/near optimal trade-offs between project duration and profit. One example is used to show the impact of extreme weather on construction time and profit. Another example is used to show the model's ability to generate optimal trade-offs between the time and profit of construction projects under extreme weather conditions.

• Journal of KIISE
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• v.42 no.7
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• pp.878-888
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• 2015

Software project planning includes several processes for estimating the effort required to complete software project tasks, allocating human resources to tasks, and creating a project plan. Because software planning is becoming more complicated as the size of software projects grow, it is difficult for project managers to decide on a reasonable project plan. To help them, many automatic software project planning approaches have been proposed. The approaches all focus on minimizing project duration. But if the plan is simply to minimize the duration, without considering software quality, the plan can harm the eventual software quality. In our research to create a reasonable project plan, we consider software quality as well as duration of the project, by defining a software quality score. The project manager can plan the project to maximize software quality for a specific project duration.

• Korean Journal of Construction Engineering and Management
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• v.15 no.6
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• pp.44-52
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• 2014

Generally, the most difficult works at scheduling are to estimate the duration of activities and linkages between them because the possibility that the duration and linkages could be exposed to the uncertainties is so high. When estimating a project duration, therefore, the probabilistic estimation of the duration as well as the probabilistic estimation of the linkages between activities should be considered concurrently. The PERT that is one of the most popular techniques applied for the probabilistic estimation of a project duration can not consider the uncertainties of the linkages because it only estimates the probabilistic duration limited to 'FS0' relationship. The purpose of this study is to propose the new method "PLET" for stochastically estimating the project duration based on the probabilistic estimation of the BDM's relationships, and also provide more wide and various probabilsitic information about the project duration by it.