Kyuman Cho

Effect of project characteristics on project performance in construction projects based on structural equation model

Most past studies that analyze project performance and the characteristics that affect such performance consist of a simple form, in which they present the brief relationship between project performance and a few characteristics that affect it. Furthermore, due to the limitations of the research methodologies used in these studies, important characteristics were often not considered in developing the relationship between project performance and project characteristics. This study aims to analyze the overall relationship between project performance and a projects characteristics. This study deduced (i) the overall causal relationship and (ii) the degree of influence between 17 project characteristics and five project performance indices. In order to achieve this goal, this study employed the factor analysis method and a structural equation model (SEM). In addition, this study established a SEM based on quantitative data from actual case studies as opposed to previous SEM studies that mainly use qualitative data. The SEM developed in this study can identify the project characteristics that affect the level of project performance required by owner in the planning stage, and is thus expected to help facilitate the decision-making process in the early planning stage of a project.

Simulation-Based Schedule Estimation Model for ACS-Based Core Wall Construction of High-Rise Building

Many existing studies about construction schedule management focus on the planning phase of a project, particularly on schedule estimation based on the labor resources involved in the project. However, equipment resources, which are another crucial factor in the productivity of a construction project, have not been considered in existing research. Therefore, this study aimed to develop a schedule estimation model considering both labor and equipment resources. For the purpose of this study, core wall construction was selected because it is a very important construction activity in terms of schedule estimation for high-rise building construction. To develop a schedule estimation model for core wall construction, an in-depth case study was conducted. On the basis of the results of the case study, a simulation model was developed using the CYCLONE method. Finally, by using the results of the simulation, a schedule estimation model for core wall construction was developed by conducting multiple-regression analysis. By using the developed model, a project manager can easily, quickly, and accurately perform schedule estimation when there are problems that may cause construction schedule delays during the construction phase.

Selection Model for Delivery Methods for Multifamily-Housing Construction Projects

Selecting an appropriate delivery method that will achieve a project’s objectives and characteristics is one of the most critical factors for the project’s success. A selection model for this study was developed by using actual construction case data in quantitative data analysis methods such as logistic regression, factor analysis, and correlation analysis. The model was developed on the basis of the design-build and design-bid-build methods from various project delivery methods. To validate the developed model, comparative tests were conducted on the selection of the delivery method for multifamily-housing construction projects, which showed that the model resulted in 95.0% accuracy. It is expected that the developed selection model will enable owners to select delivery methods that accurately meet their needs characteristics, project characteristics, and external environments.

Scheduling model for repetitive construction processes for high-rise buildings

In a high-rise building project that involves many repetitive construction processes, the effective control of such repetitive construction processes is a key factor in the success of the project. Unlike the existing scheduling methods for repetitive construction processes, a scheduling model that considers (i) the flexible job logic of the multiple work tasks that comprise a construction process and (ii) the productivity of the construction equipment and labor was developed in this paper. Various theories and algorithms such as the linking dummy, the linear scheduling method, and the production rate, were implemented in the development of the model. A scheduling model was then proposed based on such theories and algorithms and on a mathematical formula. The proposed model was verified by applying it to core wall construction, a key repetitive process in a high-rise building project. Verification showed that the developed model exhibited over 90% reliability. It is expected that the proposed model will al...

A Productivity Analysis of Tower Crane Installation Progress Based on Simulation Technique

Recently, the scale of construction work has been growing, and buildings are becoming higher. To enable greater efficiency of construction work, the use of vertical transportation equipment has been radically increasing. In this context, many studies have been conducted on tower cranes. While these studies have discussed issues such as the selection of tower cranes, the optimization of locations, and the hoisting time of tower cranes, there has been no research on the installation of tower cranes. As such, the installation of tower cranes on construction sites has been accomplished based on subjective judgment and technical assistance, and the experience of workers in equipment companies. Therefore, this study analyzes the productivity of tower cranes using simulation methodology, and proposes a generalized model of the installation process of tower cranes in order to offer a basic resource that site managers can directly utilize.

A Study on the Productivity Analysis of Deck Plate Installation Work in Steel Structure Construction

Deck plates have been widely used for steel framework due to their merits in terms of schedule reduction and work repetition. For this reason, most of the previous studies related to deck plates have focused on the development of form type and their constructability. In this study, through an actual case study and interviews with experts, a simulation model was developed using the CYCLONE method. Based on this model, this study not only analyzed the productivity of the work process of the deck plate in steel framework, but also identified the occurrence of idle time in the work process. In addition, using a sensitivity analysis, productivity and duration could be analyzed according to variation of input resources. Based on the results, this paper suggests a way to improve the productivity of deck plate work in steel frameworks. Using the model, it is expected that project managers would be able to predict the productivity and total duration of the deck plate work in the early project phase, which will enable managers to make an appropriate plan for input resources.

Decision Support Model for Determining Cost-Effective Renovation Time

AbstractThe renovation of a building, instead of raising a new structure, is being scrutinized more closely at present as a sustainable alternative for reaping the benefits of improving a building’s energy performance and mitigating its physical deterioration. The extent of the benefits would be dependent on the optimal renovation time determined through the building owner’s decision-making process. Unfortunately, only a few studies have explored improvement of the decision-making process for determining an appropriate renovation time, making it difficult for building owners to conduct reliable cost-effective renovation planning. A model that estimates the optimal cost-effective renovation time of a building therefore would be a valuable tool, and the model introduced in this paper addresses this need. By applying the model to an actual renovation project as a case study, this model yielded 24 renovation alternatives for achieving a cost-effective renovation time, from which the optimal alternative was id...

Method for Generating Multiple MRR Solutions for Application in Cost-Leveling Models

AbstractCost-leveling models have been introduced recently to minimize the fluctuations in annual maintenance, repair, and rehabilitation (MRR) costs within a multiyear infrastructure asset-managem...

Real Estate Appraisal Method for the Remodeled Office Building - Focusing of Income Capitalization Method -

Although it is reported that vacancy and lease rates of office buildings could be improved remarkably due to after remodeling work, it is difficult for the remodeled office buildings to incorporate such profitable improvement appropriately into wherein the real estate appraisal for them was conducted. Based on income capitalization method, which is one of the three current appraisal methods and considering as a proper candidate in conducting appraisal for the remodeled buildings, this paper aims at clarifying how the method can evaluate the monetary value of the remodeled office building accurately. For achieving such objective, i) the method (i.e., income capitalization method) was applied to the 25 remodeled office cases available with their market price in order to calculate their appraisal prices, ii) a comparison between the projected price by appraisal and real market price was conducted, and iii) the comparison result was analyzed in terms of how the appraisal method calculates the price for the remodeled office buildings accurately. In conclusion, it is revealed that income capitalization method can evaluate the price of the remodeled office buildings relatively accurately (9.46% of error rate in average).

Development of Checklist to Prevent Claim through Dispute Case Analysis of Public Construction Projects

Abstract Many studies on cause and prevention of claim have been carried out but they were mostly intended to come upwith the improvement measures, improvement system or the measur es to deal with the claim, which consequentlylacked the substantial ways to identify the details of claim fo r prevention purpose. That is, theres in fact no tool, inpreparation for potential claims, to identify and review the ma jor potential causes at design stage to mitigate theclaim and thus, its necessary to develop the tool such as chec klist needed to prepare the claim-supportingdocuments, check the relevant laws as well as to identify the c ause of claim. Hence the study, given the fact thatcause of claim is mostly generated at the design stage though t he claim itself tends to occur at the constructionstage, was aimed at developing the checklist based on contract document such as design documents at design stagefor public construction projects in a bid to prevent the potent ial claim occurred at the design stage.Keywords :claim, prevention of claim, design phase, checklist