• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.308-309
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• 2014

A lot of very complex free-form buildings such as Seoul City Office and DDP(Dongdaemun Design Plaza) have been recently built nowadays in domestic. However, as construction methods and cost data are decided without enough discussion and collaboration with specialized subcontractors during design stage, construction quality problems and cost overrun of the free-form buildings are thus occurred during construction stage. Therefore design system and process or contract and ordering system should be developed participating the specialized subcontractors during design stage in order to perfect the free-form design and construction. Especially US has thus an effort to apply IPD(Integrated Project Delivery) system which can solve the problems of construction quality, productivity decrease and cost overrun by constructing the buildings based on exact drawings and collaboration as well as activating BIM(Building Information Modeling). Therefore this study reviews cases of the free-form buildings in domestic and then presents necessity review of IPD in domestic.

• Journal of KIISE:Software and Applications
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• v.33 no.5
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• pp.508-524
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• 2006

We present our experience of combining, in a realistic setting, a static analyzer with a statistical analysis. This combination is in order to reduce the inevitable false alarms from a domain-unaware static analyzer. Our analyzer named Airac(Array Index Range Analyzer for C) collects all the true buffer-overrun points in ANSI C programs. The soundness is maintained, and the analysis' cost-accuracy improvement is achieved by techniques that static analysis community has long accumulated. For still inevitable false alarms (e.g. Airac raised 970 buffer-overrun alarms in commercial C programs of 5.3 million lines and 737 among the 970 alarms were false), which are always apt for particular C programs, we use a statistical post analysis. The statistical analysis, given the analysis results (alarms), sifts out probable false alarms and prioritizes true alarms. It estimates the probability of each alarm being true. The probabilities are used in two ways: 1) only the alarms that have true-alarm probabilities higher than a threshold are reported to the user; 2) the alarms are sorted by the probability before reporting, so that the user can check highly probable errors first. In our experiments with Linux kernel sources, if we set the risk of missing true error is about 3 times greater than false alarming, 74.83% of false alarms could be filtered; only 15.17% of false alarms were mixed up until the user observes 50% of the true alarms.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.354-360
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• 2009

The demands for large-scale construction projects such as Mega-projects are largely increasing due to the rapid growth of increasing populations as well as the need to replace existing buildings and infrastructure. Increasing costs of materials, supplies, and labors require the first cost estimates at the preliminary planning stage to be as accurate as possible. This paper presents the results obtained from the survey on evaluating nine critical success factors that influence the accurate first cost estimates for large-scale projects from practical experiences. It then examines the current cost structures of construction companies for large-scale projects, followed by the causes for cost and schedule overrun. Twenty completed surveys were collected and the Analytic Hierarchy Process was applied to analyze the data. The results indicate that technology issues, the contract type, and social and environmental impacts are the significant leading factors for accurate first cost estimates of large-scale construction projects.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.174-178
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• 2015

This paper presents a new method for forecasting construction project cost and time at completion or at any intermediate time horizon of the project duration. The method is designed to overcome identified limitations of current applications of earned value method in forecasting project cost and time. The proposed method usesfuzzy set theory to model uncertainties associated with project performance and it integrates the earned value technique and the contractors' judgement. The fuzzy set theory is applied as an alternative approach to deterministic and probabilistic methods. Using fuzzy set theory allows contractors to: (1) perform risk analysis for different scenarios of project performance indices, and (2) perform different scenarios expressing vagueness and imprecision of forecasted project cost and time using a set of measures and indices. Unlike the current applications of Earned Value Method(EVM), The proposed method has a numberof interesting features: (1) integrating contractors' judgement in forecasting project performance; (2) enabling contractors to evaluate the risk associated with cost overrun in much simpler method comparing with that of simulation, and (3) accounting for uncertainties involved in the forecasting project cost.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.237-238
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• 2016

Rework is a major cause that adversely affects the performance of a construction project, such as schedule delay or cost overrun. In order to prevent rework, research has been mainly conducted to analyze the cause of rework, but limited to quantitatively measure cost of rework and analyze its impact on project performance. Therefore, this paper aims to analyze impact of rework cost using 369 rework items collected from 3 construction site. This research is expected to accurately determine control target of rework and to improve efficiency of business operations in construction project.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.728-731
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• 2007

In-planned duration and cost at project closing are the two of criteria of successful project and successful project management. In Vietnam, regularly, construction projects are delayed and their costs are overrun. This research employed a questionnaire survey to elicit the causes of this situation by interviewing 87 Vietnamese construction experts. After processing data, 21 causes of delay and cost overruns appropriate with building and industrial project in construction stage were inferred and ranked. Spearman's rank correlation tests showed that there're no differences in the viewpoints between parties in project.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.419-422
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• 2002

The features of modem construction industry can be summarized as specialization, complexity, and large-scale. Therefore, increasing uncertainty of construction project can not be effectively dealt with traditional method used for construction cost management. Cost overrun affects on successful execution of managing construction project in a negative way. Therefore, accurate estimation is a priori for effective cost management. First, this work analyzes the previous cost estimation model for the effective cost management. Then, a standard structure required for developing the cost estimation model for site development was presented. In addition, the cost estimation model which can be used in planning and design phases was introduced by analyzing real site development projects.

• Journal of the Korean Society of Systems Engineering
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• v.5 no.1
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• pp.7-20
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• 2009

This paper describes a case study on the R&D programs of fighter and attacker aircraft such as F-22A, F/A-18E/F, and T/A-50. F-22A and F/A-18E/F were developed in same age. The performance of each program was, however extremely different. F-22A program results in a lot of cost overrun and schedule delay. On the other hand F/A-18E/F program met the cost, schedule, and performance goals. In the T/A-50 program with a super-sonic advanced trainer, T-50 was also developed successfully on planned cost and time by Korea Air-force and KAI. This paper derives key elements for the success of the military aircraft R&D program through lessons learned from th e case study. Each program is analyzed in terms of its background, planning and management.

• Journal of Construction Engineering and Project Management
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• v.2 no.3
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• pp.40-47
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• 2012

Construction management is essential for a achieving any pre-determined objective. It is however seen that in spite of construction management, majority of the project do not keep up their original time schedule and their completion cost is also higher as compared with the estimated cost The main reason for overrun in time and cost is that the planning at the outset of the project was not adequate or method of planning was not a refined one. In this research work, I showed the overall conditions of construction work and management in Sylhet city of Bangladesh and found many drawbacks in the construction management after completing my research. I found several factors affecting proper construction management and I have provided brief results. I have also provided some recommendations after my research work.

• Korean Journal of Construction Engineering and Management
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• v.24 no.3
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• pp.52-61
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• 2023

Conflicts in a construction project not only make negative impacts on project performance such as schedule delay or cost overrun but also require social cost to resolve the conflicts. Although the conflict needs a preemptive management because a conflict usually begins with a complaint, existing studies have focused on conflict resolution after it occurs. This study identifies and categorizes complaints which mainly appear in the construction projects. Those complaints were evaluated and quantified in terms of occurrence frequency and potential to conflict through a questionnaire survey with industry experts. Using the survey results, this study examines the characteristic of complaints in linear project and clustered project, and analyzes what kind of complaints occur by project type. As the results, this study derives the complaints with high potential to the conflicts that should be managed first during managing a construction project in each project type.