Cost Estimating and Management System for Construction Projects
There is a correlation between the efficient management of a construction project budget and success of a construction project, and the estimating accuracy of a construction cost has relation to the quantity and quality of information..In the initial phase of a construction project, due to the lack of information, there is a problem that a margin of error is wide, whereas the accuracy of foresting construction costs is low. However, from the perspective of the entire life cycle, the most influential phase of a construction project is the initial phase. Therefore, making an effort to forecast construction costs accurately in the planning and programming phases is important.
In general, the unit cost of total building floor area is used in the initial planning initial phase, and construction cost is forecasted using the actual construction cost or the standard of estimate in the programming phase. In the case that the standard of estimate is used for estimating construction costs, a cost per unit area is estimated by dividing into material cost, labor cost and expenses. And, in case of material costs and labor cost, labor per unit area is used for estimating a required quantity and costs. But, many point out that this method lack practicality.
Along with the method of estimating construction costs, some issues were found in the estimating process as well. The main problem was that there was no system estimating and managing the construction costs and the budget continuously between the planning phase and the programming phase.
For the purpose of efficiently estimating and managing the construction costs for the construction of public apartment and government buildings in the planning and programming phases, we have raised construction cost estimating methodologies for the planning/programming/schematic and mater design phases as well as the factors influencing the construction costs. In addition, we have suggested the Cost Control Point (hereinafter ‘CCP’) which can be applied to the system by grasping the construction cost estimating and management process from the viewpoint of a client. We developed a construction cost estimating model for the application of CCP reflecting the characteristics of the public apartments and government buildings. And, based on the developed model, we built a scenario-based estimating and management system for construction costs of the construction projects. Also, we made a manual for estimating construction costs, a system manual for users and a system manual for operators for the use of the system.
In addition, we developed information on the productivity which can be used in the standard of estimate which is the standard of cost estimating, and we developed the process which can be applied to the standard of estimate, scenarios and application methodologies for scenario-based integrated costing system for construction costs of the construction projects (apartment, government buildings).
The outcome of this research is as follows.