• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.263-271
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• 2013

Change orders have been widespread in both the private and public construction sectors. In particular, in the case of G2B (Government to Business) contracts, adjustment of contract price and/or schedule extension is a frequent occurrence due to change orders. To uncover the causes of change orders and suggest an appropriate strategy, this study analyzed 296 cases of change orders in military facility construction projects from 2008 to 2010. The analysis revealed that the major causes of change orders are users' additional requirements (28.38%), a change of finishing materials (23.99%), and change of footing type (17.57%), in that order. Building on the results of this analysis, the authors suggest plans for practical improvements. Specific recommendations include 1) reflect user requirements at the early stage, 2) minimize the use of additional budget due to change orders, and 3) reduce the process and time for contract amendment, among others. The results of this study may provide significant implications to those involved in military construction projects, particularly project owners (i.e., the Ministry of Defense) and contractors.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2005.11a
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• pp.117-120
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• 2005

The business market of architecture has got a system that controls a deposit according to the price function. This system is written on a law of contract about countries. So the main body of construction has to make a reasonable contract. This study is written about a rate of numerical index on controling a deposit. We tried to fine problems and solutions of labor expenses, instrument costs and material costs which is so big and changable on the construction market Labor expenses are expressed according to the rate of construction scale between direct and indirect cost that applies ability of works. Instrument costs are expressed according to an output method of a unit price annually and a weight allowance of local instrument conditions and use frequence. The last material costs expressed according to a local weight allowance make a decision of the material cost index. They applies locally relative index more than absolute one on what uses the price rate of producers and importations. This solutions are not enough to apply to the real market, so it needs to exam and to be on the market after a feasibility study.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.609-611
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• 2003

This paper presents a method for a congestion management in the competitive market which is modeled as the multiple bilateral transaction. Traditionary, the congestion management for the multiple bilateral transaction is accomplished through the process of adjustment bids. It is necessary in for the market entity to submit their price information when the congestion is occured. Finally, the ISOs can be blown about the approximated contract price of participants from the price of adjustment bids. However, the entities can submit only the amount of their contract to ISOs and ISOs are required the method to manage the congestion only by the contracted quantity. Therefore, this paper presents a method for congestion management by curtailing the only contracted quantity of market entities. To evaluated the above problem, we suggest Bilateral Transaction Distribution Factors(BTDFs), which is the sensitivity of line flow with curtailment of transactions. Using this factor, we studied about congestion management when the objective function is to minimize total curtailment of transaction.

• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.3-11
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• 2019

The construction of a facility is an act whereby infrastructure such as roads and railways and other facilities such as housing and office spaces are constructed, and due to the characteristics of the relevant industry where such construction is carried out in a custom order method, it requires a long period of time mostly. While the construction is carried out over a long period of time, fluctuations in the price of raw materials required for the construction occur. Therefore, the cost of the construction also fluctuates inevitably. The fluctuation of the construction cost meshes closely with the profit of a constructor and the efficiency of government spending. Therefore, it is necessary to maintain the construction cost at a reasonable level by adjusting the construction cost rationally in order to secure the required construction quality and spend the budget efficiently. The buffer system for solving such problem is the contract amount adjustment system by fluctuations in prices (Escalation/De-Escalation). In this study, the method combining the escalation method based on the item adjustment method was suggested for an efficient contract amount adjustment method. In addition, it is proposed that there be an investigation and codification of matters not applied to government acts and regulations on contracts related to the adjustment of fluctuations in prices legally.

• Korean System Dynamics Review
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• v.13 no.1
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• pp.81-112
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• 2012

This study investigate the impact of supply chain contracts on supply chain performance. This study employed Price adjustment contract(PAC) and Quantity adjustment contract(QAC) as two main types of a vertical coordination mechanism. We simulate different types of coordination mechanisms with various degrees of demand uncertainties and several capacity tightness scenarios. This study shows that PAC and QAC significantly enhance the supply chain profits and fill rates suggesting that supply chain performance can be improved by implementing a proper coordination mechanism depends on the level of a capacity tightness and demand uncertainty.

• Korean Journal of Construction Engineering and Management
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• v.6 no.5 s.27
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• pp.69-77
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• 2005

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative Impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results skew that ANN models give significantly improved performance compared to traditional statistical models.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.171-180
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• 2006

Change is inevitable and is a reality of construction projects. Most construction contracts include change clauses and allowing contractors an equitable adjustment to the contract price and duration caused by change. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. A number of studies have attempted to quantify the impact of change orders on project costs and schedule. Many of these attempted to develop regression models to quantify the loss. However, regression analysis has shortcomings in dealing with many qualitative or noisy input data. This study develops ANN models to classify and quantify the labor productivity losses that are caused by the cumulative impact of change orders. The results show that ANN models give significantly improved performance compared to traditional statistical models.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.175-180
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• 2010

Despite continuous efforts by the construction industry to achieve better quality, it doesn't seem that much has been improved. This is mainly because current specifications do not satisfy a change in the market environment, which is that a higher level of quality is now demanded by users. Quality improvement efforts have been satisfied merely to meet specifications. On the other hand, advanced countries have been experienced great success in their construction techniques and have reduced costs by introducing apay adjustment system to the construction industry, in which compensation is based on performance. Following their example, Koreashould introduce such a pay adjustment system in order to motivate the members of our construction industry to achieve better quality and a higher level of construction techniques. However, there has been a lack of a rational approach to the development of a system for cost coordination, as well as performance and quality inspection. Thus, in this study a legal and logical plan was developed that can be used to adjust the construction cost, along with the performance inspection of quality results, in order to introduce a pay adjustment system that is appropriate for domestic regulations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.2
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• pp.667-676
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• 2014

This study has conducted case studies in order to suggest alternatives to the historical data-based estimate system. Price fluctuation calculation methods based on historial cost indexes, standard estimate and construction cost indexes were applied to 9 road construction sites in Jeju for an analysis. As a result, in 5 construction sites (about 56% of 9 sites), the index control rate calculated based upon historical data-based estimate system was higher than that calculated based upon standard estimate and construction cost indexes. Thus the establishment of the requirements for the adjustment of contract price due to price fluctuation delays, which leads to a significant difference in price fluctuation amount. And, in an analysis of construction cost indexes, the indexes for road construction were used for calculating index control rate which ranges from 2.0 to 9.4 percent, indicating the time of construction amount and price fluctuation application has a significant influence on index control rate.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.95-102
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• 2016

Recently, a research regarding calculation of construction time extension-oriented incidental costs has been intensively suggested in quantitative aspect and recent studies on system improvement has been made continuously. In the case of Domestic Public Construction Works, State Contract Act is applied when the client is government whereas Local Government Contract Act is done when the client is local government, but more meticulous study is required because improvement plan is not proposed even there is a clear demand for improvement of these problems on calculation standard. Thus this study suggested appropriate standard by comparing each the calculation standards followed by 'State Contract Act' and 'Local Government Contract Act', considering the problems accorded, and analyzing field cases. Calculation method of other expenses was differently regulated as the revision of each regulation, and this demonstrates that there is a difference of actual cost from 12.37% to 24.95%. It is shown that less cost of construction time were calculated than actual cost according to a problem of calculation method by State Contract Act as the rate at the time of contract to be applied in other expense rate. This study suggested the rate against incidental cost and the rate of other expense per day against total construction cost as an appropriate rate calculation for other expense based on field database.