Research On Construction Cost Prediction And Control Based On System Dynamics And GM(0,n) Coupling Model

The competitive environment in the market is becoming increasingly fierce along with the increasing maturity of the construction industry.Cost is an unavoidable topic for the construction side.It is crucial for the competitiveness of the construction party to Gain the ability of cost control in construction phase,so to speak.Meanwhile,with the continuous occurrence of large-scale public health events in recent years,the control of construction costs has also been affected by many factors.Taking the COVID-19 epidemic in recent years as an example,this paper analyzes the adverse impact of many problems under the background of the COVID-19 epidemic,such as the extension of project duration,the loss of construction personnel,and the increase of cost expenditure in a short time on the cost control in the construction stage.And this paper couples the GM(0,N)model with the system dynamics model,establishes a simulation model of cost control in the construction phase under the background of the novel coronavirus pandemic.The GM(0,N)model is used to predict the cost data of the complete construction stage,and then the system dynamics model is used to apply the possible impact of COVID-19 on the cost data.The main purpose of the model is to predict and simulate the construction cost after the occurrence of emergencies by using the existing construction phase cost.According to the simulation results,cost control measures are taken in advance to ensure that the final construction phase cost is within the scope of the planned cost.The article consists of the following parts.Firstly,this paper introduces the research background and significance of the adverse impact of COVID-19 on the construction industry,the main problems existing in the current construction cost control,analyzes the research status at home and abroad,and sorts out the relevant concepts and theories to pave the way for the solution of the following problems.Secondly,according to the cost composition,the construction stage cost is divided into14 sub-projects.The research boundary of the cost of the construction phase affected by the COVID-19 epidemic was divided by literature analysis method and field survey method.Finally,in order to establish the cause-and-effect diagram of cost factors in the construction phase based on the realistic situation,10 factors affecting construction costs during the period of COVID-19 are identified from three aspects within the scope: material loss rate,cost control measures,epidemic prevention cost,construction efficiency reduction cost,labor cost increase rate,building materials and machinery cost increase rate,government policies,workers’ professional quality,construction technology management level,and unit time plan control cost.Finally,the GM(0,N)model is used to predict the later cost of the project from the construction cost data before the occurrence of COVID-19 provided by a resettlement house project example.According to the actual situation of a resettlement house,the stock flow diagram of the system dynamics model is established by VENSIM software on the basis of the causal relationship diagram,and the relationship equation between variables is input to form a complete SD model.Finally,the GM(0,N)prediction results are substituted into the SD model for cost control simulation.Based on the analysis of the simulation results,the influence degree of different influencing factors on the cost of the construction phase under the novel coronavirus outbreak is obtained,and according to the analysis results,cost control measures are proposed :(1)to strengthen the cost management policies;(2)Cost control measures suit the case;(3)Pre-job awareness training and regular assessment;(4)Adopt a reward and punishment mechanism for the construction personnel;(5)Implement pre-job and in-job skill training.In conclusion,it proves that the coupling of GM(0,N)model and system dynamics model is practical for the prediction and control of construction cost in COVID-19 environment,and provides new ideas for the prediction and control of construction cost under emergencies in situations in the future.