| With the rapid development of China’s economy and the continuous acceleration of urban construction,shantytown renovation is an important part of urban construction,and the project of renovation dilapidated house is one of shantytown renovation projects.Whether the total project cost estimation is reasonable is not only related to the smooth progress of the project,but also related to whether the project can greatly improve the housing problem,so it is significant to determine the total project cost.However,it has some complex and changeable factors in this kind of project,which contains some elements of risk.That caused a great variety of project.So the cost estimation of the project is needed to research duing to the variation.In this paper,the reason why the cost of completion far exceeds the cost estimate is analyzed,based on the current situation of the renovation of dilapidated houses in Nanning,Guangxi and China.Then,it is found that the reason of large deviation in cost estimation is due to the lack of reasonable estimation method and insufficient risk consideration.Therefore,the fuzzy exponential smoothing method,system dynamics method and Monte Carlo method are used to obtain a more reasonable cost.In this paper,the project cost estimation is divided into three stages.In the first stage,the civil engineering cost estimation is improved.the civil engineering cost of new projects is determined by fuzzy mathematics,depending on some similar project cost datas.And the calculation contents and methods of other construction costs are improved in combination with the characteristics of the old and dangerous projects.In the second stage,the project cost is improved,and the risk factors of project cost overruns are analyzed.Based on the risk factors,the system dynamics model of project cost deviation is established and simulated to determine the project cost under the risk factors.In the third stage,the total cost of the project is optimized.Based on the uncertainty of each cost,the probability distribution function of each cost is determined by PERT method,and Monte Carlo method is selected for simulation to obtain the change interval of the total cost of the project,and the final total cost is determined according to the decision-making requirements of the construction unit.At last,through the case analysis of the actual project of changing dilapidated houses into housing,it is concluded that the total cost value determined by the above method is closer to the actual cost of completion than that determined by the traditional investment estimation method,which is proved that the cost estimation method in this paper is reasonable.So the cost can be predicted reasonably and a more scientific decision for the construction unit can be provided by this method. |
