Cost Control And Analysis Of The Prefabricated Building Based On System Dynamics

Prefabricated building is a new type of construction that is vigorously promoted by governments,from national to local levels,but the high construction cost has become a main factor hindering its development.Looking into the cost structure of prefabricated building,a major part is the cost of assembled precast concrete components(referred to the cost of PC component).Therefore,it is necessary to study and quantify the factors affecting the cost of PC components from a systematic perspective,compare the degree of influence of each factor to find the key ones,and provide theoretical guidance on the cost control of prefabricated buildings.In brief,this paper summarizes the factors affecting the cost of PC components by analyzing both domestic and international researches in the field of applying systematic dynamics to study cost control of prefabricated buildings.Meanwhile,this paper also verifies major ones of these factors by using structural formulation models.Firstly,the basic theories involved in this study will be introduced,including the concept,characteristics,composition and control significance of the cost of prefabricated buildings.Besides,the basic principles,characteristics,usage methodology and modeling methods of systematic dynamics will be covered.The basic principles and analysis steps of structural formulation modeling are explained,and then the necessity and applicability of systematic dynamics methods and structural formulation models for the cost control study of PC components of prefabricated buildings are analyzed and demonstrated.Secondly,by combining the actual situation of the prefabricated building market in Jiangsu Province,in 2019,the purpose and limitation of the modeling work is clarified.Out of the concerns of simplicity,the cost components of PC components of prefabricated buildings are screened,and qualitative and quantitative analysis of the cost components of PC components,external influences and cost savings are conducted using systematic dynamics.Qualitative and quantitative analysis of these influencing factors such as external influence,external influence and cost saving,and the system dynamics causal relationship loop diagram and the stock flow diagram are drawn,and the equations are established and assigned to the parameters in the stock flow diagram.After establishing the systematic dynamics models of PC component cost,the structural formulation models are established through the data collected from the questionnaire,and the structural formulation model was examined through the confidence analysis and effectiveness analysis to verify the reliability of the systematic dynamics model.Finally,a simulation analysis of the systematic dynamics model is conducted to analyze the influences of tax rate adjustment,government promotion and progress incentive changes on the cost changes of PC components of prefabricated buildings.The findings indicate that if all other conditions held constant,lowering the tax rate,appropriately increasing government promotion and increasing progress incentive can reduce the cost of PC components of prefabricated buildings.This paper proposes a cost control strategy for prefabricated buildings from the perspective of the cost composition of precast concrete components,and provides recommendations for promoting the development of prefabricated buildings.