• The Journal of the Korea Contents Association
• /
• v.16 no.8
• /
• pp.661-670
• /
• 2016

In 2000, post-construction evaluation was introduced for the purposes to evaluate demand, cost, and construction period of public construction projects and to reduce errors of public order agencies. However, pricing guide of post-construction evaluation has not been established, which becomes a cause of quality degradation of post-construction service and conflict occurrence. This study suggests the pricing guide in the form of percentage of construction cost method and cost plus fee method based on data of post-construction evaluation. This study investigates the construction costs and service costs for post-construction evaluation and conducts the comparative analysis of 'percentage of construction cost method' and 'cost plus fee method.' The analysis result shows 'cost plus fee method' is more accuracy than 'percentage of construction cost method.' In particular, cost plus fee method includes various correction coefficients, such as distance, area, and integration, in order to reflect the project characteristics of each infrastructure, and suggests linear construction (roads, railways), nonlinear construction I (housing and industry complex), and nonlinear construction II (airports, seaports, dams, water and sewage).

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.5
• /
• pp.518-527
• /
• 2012

This study uses a hybrid estimation tool for effective cost data management of building projects, and develops a realistic cost estimation model. The method makes use of newly available information as the project progresses, and project cost and percentage progress are analyzed and used as inputs for the developed system. For model development, case-based reasoning (CBR) is proposed, as it enables complex nonlinear mapping. This study also investigates analytic hierarchy process (AHP) for weight generation and applies them to a real project case. Real case studies are used to demonstrate and validate the benefits of the proposed approach. By using this method, an evaluation of actual project performance can be developed that appropriately considers the natural variability of construction costs.

• Journal of the Korea Institute of Building Construction
• /
• v.16 no.5
• /
• pp.463-470
• /
• 2016

Construction companies calculate their revenues and costs from constructing activities using the 'Percentage of Completion Method', which is based on ratio of actual construction cost to total costs estimated. The reliability of the net profit of construction companies is being evaluated lower than other industries due to incorrect application of 'Percentage of Completion Method' to cover losses actually occurred. Therefore, the purpose of this study is to verify the quality of earnings calculated based on 'Percentage of Completion Method' in terms of information usefulness. Results from empirical analysis show that investors in stock market underestimate the value of the construction companies' earning information by applying 'Percentage of Completion Method' and not actively use in investment decision making. Accordingly, it has been confirmed that the association between income information and stock prices falling. These results suggest the need for strict supervision of the supervisory authorities and the practical application of 'Percentage of Completion Method' in reliability.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.3
• /
• pp.152-164
• /
• 2015

Enhancing clarity and transparency of the pricing guide for technical services for public construction works enables the prediction and reimbursement of the service cost for project owners and bidders, while it would also yield benefits for engineers who carry out the construction tasks. In order to improve the global competitiveness of construction service industry, the government revised its pricing guide for techical services for construction works recently, moving away from its previous percentage-of-construction-cost method towards the Cost Plus a Fee Method. However, since the Cost Plus a Fee Method results in the rise of the service price by 153%~197%, there is the need for a review on the method and basis of the adjustment in order to avoid controversies regarding the application of the revised method. In this context, this paper analysed the 2014 revision of the pricing guide for technical services for public construction works through comparison with foreign cases including those of the US and the UK. The analysis yielded the conclusion that, while the shift towards Cost Plus a Fee Method which is widely used in advanced economies is a very meaningful change in large measure, certain aspects still remain problematic. Unlike in advanced economies, the detailed break-down shows the direct labor cost includes certain indirect expenses. Also, indirec expenses are admitted so comprehensively as to include overhead costs and technology royalties. These problems results in redundant estimation of certain expenses, and obstructs transparency in spending details. This paper proposes various improvement measures to address these issues.

• Journal of the Korea Institute of Building Construction
• /
• v.6 no.3 s.21
• /
• pp.115-122
• /
• 2006

This study is aimed to get clear model for CM fee level in public construction project. For the practical use and main target, CM for fee contract only is assessed and analysed. Cost estimate by percentage of total contract sum and method based on the historical construction data have significant deficiency. An regression model and probabilistic model are suggested with 9 independent variables. In the case of limited work scope, an element based floor area model is suggested and concluded with fish-bone scheme.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.124-125
• /
• 2013

The purpose of this research is to propose an approximate estimation system for Modernized Hanok. Mock-up (Jisinjae) site data has been collected and analysed to characterize the modernized Hanok and to examine the range of cost fluctuation rate with each work items. As a result, number of floor, area (㎥), shape, methods and materials were considered as key factors for price change on the total construction cost. Furthermore, wood structure (34%) and roof (17%) account for major cost percentage. The cost fluctuation rate of two factors were -3.3%~+5.6% (wood structure) and -4.1%~+4.2% (roof). For further research, existing method will be analysed in order to developing the Hanok estimation system. And the cost fluctuation rate of every work items will be continually evaluated.

• Korean Journal of Construction Engineering and Management
• /
• v.1 no.1 s.1
• /
• pp.63-71
• /
• 2000

The paper considers two non-deterministic methods of analysing the risk exposure in a cost estimate The fist method(referred to as the 'conventional statistical' method) analyses cost data directly, to describe a probability distribution for total cost. The second method(referred to as the 'Monte Carlo simulation' method) interprets cost data directly, to generate a probability distribution for total costs from the descriptions of elemental cost distribution. The common practice of allowing for risk through an all-embracing contingency sum or percentage addition is challenged. Rather than excluding conventional, non-deterministic methods, they are here presented as possibly the only of effective foundation on which to risk management in cost estimating.

• Korean Journal of Construction Engineering and Management
• /
• v.19 no.6
• /
• pp.124-134
• /
• 2018

Despite the many advantages of modular housing, low preference for modular housing for consumers who are familiar with RC structure leads to high construction cost of modular housing. The cost of modular buildings is about 130% of that of RC structures, so it is urgent to secure economical efficiency of modular buildings. Therefore, in this study, after calculating the savings amount of modular housing by type of construction work, economic analysis was conducted from a long - term perspective. In order to carry out the research, the authors compiled and analyzed the material cost, labor cost, and expenses incurred by each type of work by reclassifying the statement of the modular housing into the factory production and the site installation. After that, Pareto diagrams were created to find a core work that is included in the cost ratio of about 80%, and selected it as a cost reduction subject. Based on the assumption that the market size of domestic modular housing is similar to the level of modular advanced countries such as Japan and European countries, six cost reduction methods were set up that reflects the characteristics of the modular construction method and used for the expert interviews. Cost saving potentials in percentage from the interview were converted to the amount of savings that can be achieved by each type of method when applying the method. Finally, the findings of the study are expected to suggest long-term directions for technical development for modular construction and cost savings.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.4
• /
• pp.139-145
• /
• 2015

Modular construction is combined with manufacturing production process and conventional construction industry technique. Considering characteristic of modular construction production process, manufacturing facilities require indirect costs for utilities, equipment, and overall maintenance, which can affect modular units pricing. However, current modular construction cost classification is inadvertent to reflect the manufacturing overhead costs, because it is generally added as a percentage to sum of labor, material and equipment as it called in single cost pool used. This process is easy to estimate the total construction cost at the project starting points, but it brings on misunderstanding of project profit estimations by "cross subsidization phenomenon". To prevent this situation, in this research aims to provide modular construction overhead cost handling process at the detailed indirect cost calculation for manufacturing stage using Activity-Based Costing as one of the powerful method for overhead costs estimation and allocation. Using this research results, modular construction cost estimators have more detailed cost information of modular units and prevent to misallocate indirect costs. Also, it can be utilized to aid the understanding of the company's profit structure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.146-147
• /
• 2017

Recently, as the living standards of residents in apartment houses continued to improve, the dispute of post management have also increased. one of the Issue, Concrete Cracks comprised high percentage of dispute. Especially, between criteria the cost of repairing defect and the judgement of defect isn't clear, they are a lot of dispute in this regard. Even though lots of the criteria about Inter-layer crack is existed by judging defects, In a court, they are judging their own criteria about Inter-layer crack. The purpose of this study is to compare and analyze Defect Judement Standard both MOLIT and Court, and to provide the Improvement for Defect Judgement and Repair Method of Inter-layer concrete crack.