| For sake of the carbon peaking and carbon neutrality goals,it is a reached consensus in construction industry that its traditional way of construction needs to be transformed to prefabricated construction.Since 2010,some large construction enterprises in China have begun to experiment with prefabricated construction projects.However,this transformation requires a reform of the whole industrial mode and cooperation among enterprises in the industrial chain.For lack of such supports,prefabricated construction projects were not promoted at an ideal speed in China.During the promotion and application of prefabricated construction projects,many scholars have conducted a lot of technical researches,including component decomposition design,component material development,assembly technology research and development,BIM technology promotion,etc.,but there has been little attention paid to management aspects such as the way of construction,management methods,and cost control.In fact,the costs of prefabricated construction involve multiple aspects during its promotion and application,including not only direct construction costs,but also many hidden costs that are often ignored,such as environmental protection costs.Previous cost control theories usually focused on costs measurement after their occurrence,lacking the foresight of cost management.Therefore,there is an urgent need for a systematic and predictive theory to guide cost control practices.The object of this dissertation is the comprehensive cost control of prefabricated construction projects.By systematically simulating costs and evaluating cost control,this dissertation studied the comprehensive cost of prefabricated construction projects from production to construction.This is of great significance for improving the management of prefabricated construction projects.The main work of this dissertation is as follows: First,based on the sorted relevant literature,20 key factors affecting the cost of prefabricated construction projects were determined through discriminant analysis,reliability testing,and exploratory factor analysis.Second,based on these key factors,a dynamic simulation model of the comprehensive cost control system for prefabricated construction projects was established,which includes five subsystems of direct construction costs,quality costs,safety costs,environmental protection costs,and time costs,as well as two second-level subsystems of project costs and total costs.The model was tested in terms of boundary suitability,structural evaluation,and parameter estimation.The model was globally optimized in terms of the comprehensive cost control of prefabricated construction projects.Third,the weight of key factors was determined with the method of the triangular fuzzy number,and the cost control level evaluation model was constructed with the application of the trapezoidal two-dimensional linguistic power generalized integration operator.Finally,three similar cases were selected,and the simulation,optimization,and evaluation of cost control were conducted under the established dynamic simulation model and evaluation model.The innovation of this article is demonstrated in the following aspects: Firstly,on the basis of a comprehensive cost control system of prefabricated construction,a cost control simulation model is established.The model includes seven subsystems and uses policy optimization function of system dynamics software for global optimization,thus obtaining the optimized minimum costs.Simulation calculations make it possible to determine the direction and available extent of improving cost control.Secondly,the structural equation model in statistics is applied to distinguish and test 20 key factors that affect the costs of prefabricated construction through discriminant validity test,reliability test,exploratory factor analysis and confirmatory factor analysis.These factors are fundamental for not only the dynamic simulation of the cost control system but also evaluating the level of cost control.Finally,this dissertation constructs a cost control evaluation index system for prefabricated construction,and proposes an evaluation method based on the trapezoidal two-dimensional linguistic power generalized integration operator.The first dimension of the two-dimensional linguistic information is expressed in the form of trapezoidal fuzzy numbers,which covers more complete and effective information and avoids the loss of evaluative information.The power generalized integration operator can take advantage of the mutual support degrees between attribute indicators to determine a more reasonable and effective comprehensive weight,assigning lower weights to some relatively unreasonable data(such as extreme values),thereby eliminating the scoring bias of some evaluation experts.Through the research on the comprehensive cost control of prefabricated construction,three conclusions are drawn.Firstly,the 20 indicators selected for the cost control management evaluation system of prefabricated construction have certain breadth and reliability and good applicability.Secondly,the comprehensive cost management of prefabricated construction can be divided into five subsystem models,including direct construction costs,quality costs,safety costs,environmental protection costs,and time costs,and two auxiliary subsystems.The seven systems are interrelated and ultimately form the overall system of comprehensive cost management.Finally,the evaluation method based on the trapezoidal two-dimensional linguistic power generalized integration operator can process evaluation information in a more accurate way.It is closer to the real decision-making environment and suitable for the cost control management evaluation of prefabricated construction. |
