Research On Construction Schedule Risk Management Of Prefabricated Project Based On System Dynamics

As prefabricated buildings reduce wet work on site,reduce environmental pollution,energy saving and environmental protection;while prefabricated components are processed in the factory,they are also being constructed and assembled on site,which not only improves production efficiency,but also saves the template and the traditional construction process.The number of scaffolding;the prefabricated building adopts industrialized production methods,which also effectively solves the problem of lack of labor.Therefore,in recent years,the country has issued a series of related policies and regulations to promote the development of prefabricated buildings.However,in actual projects,prefabricated buildings often cannot be completed on schedule.Compared with traditional buildings,prefabricated buildings require a higher degree of coordination among various workplaces,and the technical system of prefabricated buildings in my country is not perfect,and at the same time lacks mature on-site management experience.Various factors such as damage to components and return to the factory,worker experience Insufficiency caused the project construction progress to be affected.Therefore,it is necessary to conduct in-depth research on the prefabricated construction schedule risk factors to improve the efficiency of prefabricated construction schedule management.Although the existing risk management methods are helpful to the research of project schedule risk,they lack the mutual influence analysis of the complex relationship of factors and cannot cope with the extensive and complex schedule risk of prefabricated construction.Based on literature research and investigation and research,this paper uses entropy weight method and system dynamics analysis method to identify the schedule risk of prefabricated buildings in the construction phase,and quantitatively analyze and evaluate the impact of risk on schedule.The main research contents of this paper are as follows:(1)Based on the literature research,analyze the construction schedule factors and schedule risk factors of prefabricated buildings,establish the construction schedule factor relationship model,and initially identify 16 schedule risk factors;further through the questionnaire survey,adopt The entropy method finally determined the key schedule risk factors of 10 prefabricated construction projects,including disordered component stacking,immature temporary support technology and lack of professional and technical workers.(2)Establish an analysis system based on the construction schedule factor relationship model and 10 schedule risk factors to clarify the modeling purpose and boundaries of the system dynamics,that is,to establish an analysis system for "prefabricated construction delays" to simulate the impact of construction schedule risk factors The impact of the prefabricated construction period,the causal circuit diagram is constructed with the help of system dynamics software,and the relationship between the prefabricated construction schedule risk factors is qualitatively described.Based on the relationship between schedule factors,determine level variables and rate variables,and convert the causal loop diagram into a system stock flow diagram;at the same time,establish system equations for each parameter in the stock flow diagram based on relevant literature and survey results to complete system dynamics modeling,To realize the quantification of risk impact in the model.(3)Use the Delphi expert survey method to assign the initial value of the system boundary,that is,the schedule risk factor,and assign the initial value of the key schedule factor based on the case,and then simulate the established system dynamics model,and observe the value of the risk factor by changing the parameter assignment For the changing trend of the completion period of prefabricated buildings,key risk factors such as insufficient standardization of component design,inadequate construction technology disclosure,and lack of prefabricated lifting workers are determined.(4)Finally,this article proposes the use of BIM technology to deepen the design of prefabricated components and the use of Navisworks to simulate the hoisting process and other optimization countermeasures for the risk factors that have a greater impact.The system dynamics model established in this paper quantitatively analyzes the impact of schedule risk factors on the construction period,provides a reference for management personnel in construction schedule management and control,is conducive to improving the efficiency of prefabricated building schedule management,and promotes the rapid development of prefabricated buildings in my country.The innovations of this article:(1)Based on literature research,identify and summarize the relationship model of the prefabricated building construction schedule factors and schedule risk factors,and provide the basis for the prefabricated building construction schedule risk management.(2)Established a system dynamics prefabricated building construction schedule risk management model to quantify the impact of risk factors on the prefabricated construction period.(3)Based on model simulation results and analysis,put forward key risk control strategies,and closely link risk analysis,risk evaluation,and risk management and control.