The system theory is applied to construct the BIM application project system project. Through the analysis of relationship among different variables, the stock flow graph is drawn to simulate and measure the economic benefits of BIM application in projects. The Vensim software is applied to draw the inventory flow graph and to test the model. According to the analysis on actual application of the project, the project data is extracted, and the Vensim software is applied to conduct simulation to obtain the benefit of BIM application in projects with more reasonable calculation process and more accurate calculation result. Influencing factors, including engineering cost, engineering error rate, engineering rework rate, working hours, working intensity, fatigue, management assistance, and etc., are all selected to compare and analyze the data of projects without applying BIM technology, and to analyze the impact of projects with BIM application, verifying the rationality and feasibility of the model.

As a newly emerged technology, the BIM technology still possesses many uncertain factors or uncertain trends in the future. Under the background of BIM application in the whole industry, it is generally believed in the whole industry that BIM technology can bring higher economic value, which, however, lacks of strong support of evaluation system. Based on the characteristics of BIM technology, this paper determines the performance evaluation index through integrated methods of questionnaire survey and literature induction, and also establishes a performance evaluation system of engineering projects of BIM technology by using the analytic hierarchy process and fuzzy comprehensive evaluation. The established BIM project performance evaluation system is then applied in a BIM pilot project which has completed acceptance to conclude comprehensive evaluations of the performance of the project.