Research On Construction Schedule Management Of Assembly Building Based On SD Method

In recent years,the construction industry,in response to the national concept of low-carbon development and in search of further development,has decided to abandon the traditional construction mode of relying on manual work and on-site pouring,and to develop an assembled building model with standardized design,factoryized production,assembled construction and informationized management.Because of its own characteristics and advantages,the country has introduced a series of policies to promote the development of assembled buildings in recent years,but in the actual construction process,assembled buildings are often not completed as planned.The requirements of assembled buildings are much higher than those of traditional buildings in terms of the synergy between various tasks,while the development of assembled buildings in China started late,and many technologies are still immature and cannot form a perfect system,and there is also a lack of mature on-site management experience at the management level,resulting in many factors affecting the progress of assembled buildings.Therefore,it is necessary to conduct an in-depth study on the factors affecting the progress of assembled buildings in order to improve the efficiency of assembled building schedule management.Although the existing project schedule management methods are helpful for the study of assembly building schedule management,the interactions and connections among the influencing factors cannot be analyzed effectively.This paper identifies and screens the factors influencing the construction schedule of assembled buildings based on literature research and field studies,and combines hierarchical analysis,Delphi method and system dynamics methods to analyze the identified influencing factors qualitatively and quantitatively,and to quantify the impact of each factor on the schedule of assembled buildings.The main research conducted in this paper is as follows:(1)Analysis of the factors influencing the construction schedule of assembly buildings,mainly including the analysis of construction schedule influencing factors,identification,screening and determination of the factors influencing the construction schedule of assembly buildings,in order to lay the foundation for the construction of the system dynamics model afterwards.The 14 factors affecting the construction schedule were identified through literature research and study,and then the influencing factors were screened according to questionnaire survey and hierarchical analysis,and finally 9 key influencing factors were identified for the next step of research.(2)Construct the dynamics model of construction schedule management system of assembly building.Firstly,the purpose and boundary of constructing the system dynamics model were clarified according to the analysis of the influencing factors and 9 key influencing factors of the construction schedule of the assembly building,and the overall structure and system variables of the construction schedule management system of the assembly building were determined.A causal loop diagram of the assembly building construction schedule management system was established using Vensim software to characterize the interrelationships among the factors,and then a stock flow diagram was constructed according to the types of causal loop diagram and system variables.After determining the parameter equations of each variable through literature research and other means,the Delphi method was applied to assign values to the nine key influencing factors,and finally,after importing the determined parameter equations and values into the system,the construction of the system dynamics model was completed.(3)The values assigned to the influencing factors by the Delphi method were used as the initial values for the simulation of these factors,and then 10 scenarios were designed for the simulation by changing one value and keeping the other values unchanged.Through the analysis of the simulation results,four key influencing factors that have the greatest impact on the construction schedule are identified,namely,lack of experienced technical workers for lifting,inadequate technical briefing of technicians,poor registration and chaotic stacking of components and low standardization of prefabricated components design.(4)According to the identified key influencing factors,countermeasures such as establishing an information exchange platform to improve the accuracy of component information registration and using Revit and other deepening design software to improve the standardization of prefabricated component design were proposed.The construction schedule management system dynamics model of assembly building constructed in this paper is conducive to improving the construction schedule management mode and improving the efficiency of schedule management,which is conducive to promoting the development of assembly building in China.