Prefabricated construction technology system evaluation method based on project performance

Abstract

The invention discloses a project performance-based prefabricated construction technology system evaluation method, and belongs to the field of civil engineering project management. According to the method, the problem of poor evaluation accuracy caused by subjectivity of qualitative evaluation in an existing prefabricated construction technology system evaluation method is solved. The method comprises the following steps: dividing an assembled construction technology system project into three stages, constructing a multi-input-multi-output evaluation index system, and collecting input and output data of different stages of the assembled construction project of a target structure system; constructing a three-stage super-efficiency EBM model, and obtaining the total performance of the completed prefabricated construction project and the performance of each construction stage of the target structure system by using the three-stage super-efficiency EBM model and the collected data; and comparing and evaluating different prefabricated construction technical systems adopted by the target structure system according to the total performance and the performance of each construction stage. The method is mainly used for evaluating the prefabricated construction technology system.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering project management. Background Art

[0002] With the rapid advancement of global urbanization, the demand for infrastructure and residential buildings is increasing. Prefabricated construction has become a development trend in the global construction industry due to its characteristics of saving labor resources, shortening construction time and significantly improving building quality. Existing studies mainly qualitatively evaluate the advantages and disadvantages of different prefabricated construction technology systems from the aspects of cost, construction quality and supply chain resilience. These qualitative evaluation methods will lead to inaccurate results due to the subjectivity of the evaluation. Therefore, quantitatively evaluating the technology system through the project performance measurement results and analyzing the driving factors of different technology systems affecting project performance is currently a hot topic in the research of prefabricated construction project management.

[0003] At present, there are two main methods for quantitatively measuring the performance of prefabricated construction projects: the balanced scorecard (BSC) and the data envelopment analysis (DEA). The DEA method can collect and analyze the data of each project by selecting appropriate input and output indicators, and compare the input and output of the decision-making unit by constructing a linear programming model to evaluate the relative efficiency of multiple decision-making units. Compared with the BSC method, the DEA method does not need to assume a specific production function, saving a lot of time, resources and personnel to design indicators, collect data and evaluate the value of indicators, reducing the complexity of measurement and avoiding the influence of subjective decision-making on the measurement results. However, the shortcomings of the DEA method are also obvious. It ignores that the prefabricated construction project is a complex production system, which includes prefabricated component production, transportation, assembly and other links, and there may be radial and non-radial changes in input and output in each link. At the same time, the DEA method does not take into account that the prefabricated construction project is a complex process that includes the production, transportation and construction of prefabricated components, and there are obvious differences in the construction process of prefabricated construction projects with different technical systems. A method that can accurately measure the performance of prefabricated construction projects is needed to improve the effectiveness of the evaluation. Summary of the invention

[0004] In order to solve the problem that the qualitative evaluation adopted in the existing evaluation method of prefabricated construction technology system is subjective and causes poor evaluation accuracy, the present invention provides an evaluation method of prefabricated construction technology system based on project performance.

[0005] The present invention provides a method for evaluating an assembly construction technology system based on project performance, comprising:

[0006] Step A1: Divide the prefabricated construction technology system project into three stages, construct a multi-input-multi-output evaluation index system, and collect input and output data of different stages of historical construction projects with the same target structural system according to the evaluation index system;

[0007] The three phases mentioned include the production phase, transportation phase and construction phase of a building project;

[0008] Step A2: construct a three-stage super-efficiency EBM model, and use the input and output data of the different stages combined with the three-stage super-efficiency EBM model to obtain the total performance and efficiency of different stages of historical construction projects with the same target structural system;

[0009] Step A3: Compare the overall performance and performance at different stages of historical construction projects with the same target structural system, obtain the overall performance ranking of different technical systems under the target structural system and the performance differences at different stages of different technical systems, and conduct an overall and phased evaluation of the technical system for constructing the target structural system.

[0010] Furthermore, in the present invention, in step A1, the multi-input-multi-output evaluation index system includes:

[0011]

[0012] Furthermore, in the present invention, in step A2, the formula of the three-stage super-efficiency EBM model is:

[0013]

[0014]

[0015] Where r * To build project performance for assembly; i is the slack variable of the i-th input factor; j is the decision-making unit; n is the total number of DMUs; w i The importance of the input indicator is satisfied X ij and Y rj are the i-th input factor and the r-th output factor of decision-making unit j respectively; x ik and rk are the i-th input factor and r-th output factor of decision-making unit k respectively; m and s are the number of inputs and outputs respectively; θ is the planning parameter of the radial part; λ j is the linear combination coefficient; ε x is the key parameter, satisfying 0≤ε x ≤1.

[0016] Furthermore, the present invention also includes a method for analyzing factors affecting performance, the method comprising:

[0017] Step B1: Compare the differences in different stages of all technical systems in building the target structural system and extract the factors that affect the performance;

[0018] Step B3: Construct a Tobit model, and use the factors that affect performance and the performance of historical construction projects at different stages described in Step A2 in combination with the Tobit model to obtain regression coefficients of the influencing factors; and use the regression coefficients to obtain the degree of influence of different influencing factors on performance at different stages.

[0019] Furthermore, in the present invention, in step B2, the method for extracting factors that affect performance is: comparing and analyzing differences in production methods, transportation methods, and construction methods to obtain factors that affect performance.

[0020] Furthermore, in the present invention, in step B2, the formula of the Tobit model is:

[0021]

[0022] Where Y l Represents the project performance results, x l is the quantitative index of each influencing factor, l is the decision-making unit number, β T is the regression coefficient of the influencing factor, ε l is the error term.

[0023] The method of the present invention includes collecting assembly construction project data; constructing a multi-input-multi-output evaluation index system based on the assembly construction project data; calculating the performance of the assembly construction project based on the three-stage super-efficiency EBM model and the multi-input-multi-output evaluation index system; evaluating the technical system based on the performance measurement results of the assembly construction project; comparing the differences of different technical systems at different stages of construction and extracting influencing factors; using the Tobit regression model, calculating the parameter value, sample mean and variance of the Tobit model, identifying the dominant factors, and determining the main driving factors of the performance of the assembly construction project. The accuracy of performance measurement and the speed of comparative evaluation of multiple technical systems are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a flow chart of the method of the present invention;

[0025] Figure 2 It is the schematic diagram of the three-stage super-efficiency EBM model;

[0026] Figure 3 This is a comparison chart of the two technical system component forms. The left side of the figure is the PC technical system component form diagram, and the right side is the PMC technical system component form diagram;

[0027] Figure 4 This is a comparison chart of component transportation methods. The left side of the figure shows the transportation method diagram of the PC technology system, and the right side shows the transportation method diagram of the PMC technology system.

[0028] Figure 5 This is a comparison chart of the connection methods of two technical system components. The left side of the figure shows the connection method of PC technical system components, and the right side shows the connection method of PMC technical system components. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0030] Specific implementation method 1: refer to Figure 1 Specifically describing this embodiment, a method for evaluating an assembly construction technology system based on project performance described in this embodiment includes:

[0031] Step A1: Divide the prefabricated construction technology system project into three stages, construct a multi-input-multi-output evaluation index system, and collect input and output data of different stages of historical construction projects with the same target structural system according to the evaluation index system;

[0032] The three phases mentioned include the production phase, transportation phase and construction phase of a building project;

[0033] Step A2: construct a three-stage super-efficiency EBM model, and use the input and output data of the different stages combined with the three-stage super-efficiency EBM model to obtain the total performance and efficiency of different stages of historical construction projects with the same target structural system;

[0034] Step A3: Compare the overall performance and performance at different stages of historical construction projects with the same target structural system, obtain the overall performance ranking of different technical systems under the target structural system and the performance differences at different stages of different technical systems, and conduct an overall and phased evaluation of the technical system for constructing the target structural system.

[0035] Furthermore, in the present invention, in step A1, the multi-input-multi-output evaluation index system includes:

[0036]

[0037] Furthermore, in the present invention, in step A2, the formula of the three-stage super-efficiency EBM model is:

[0038]

[0039] Where r * To build project performance for assembly; i is the slack variable of the i-th input factor; j is the decision-making unit; n is the total number of DMUs; w i The importance of the input indicator is satisfied X ij and Y rj are the i-th input factor and the r-th output factor of decision-making unit j respectively; x ik and rk are the i-th input factor and r-th output factor of decision-making unit k respectively; m and s are the number of inputs and outputs respectively; θ is the planning parameter of the radial part; λ j is the linear combination coefficient; ε x is the key parameter, satisfying 0≤ε x ≤1.

[0040] Furthermore, the present invention also includes a method for analyzing factors affecting performance, the method comprising:

[0041] Step B1: Compare the differences in different stages of all technical systems in building the target structural system and extract the factors that affect the performance;

[0042] Step B3: Construct a Tobit model, and use the factors that affect performance and the performance of historical construction projects at different stages described in Step A2 in combination with the Tobit model to obtain regression coefficients of the influencing factors; and use the regression coefficients to obtain the degree of influence of different influencing factors on performance at different stages.

[0043] Furthermore, in the present invention, in step B2, the method for extracting factors that affect performance is: comparing and analyzing differences in production methods, transportation methods, and construction methods to obtain factors that affect performance.

[0044] Furthermore, in the present invention, in step B2, the formula of the Tobit model is:

[0045]

[0046] Where Y l Represents the project performance results, x l is the quantitative index of each influencing factor, l is the decision-making unit number, β T is the regression coefficient of the influencing factor, ε l is the error term.

[0047] The present invention constructs a three-stage super-efficiency EBM model, which avoids the traditional performance measurement method that usually regards each stage in the assembly construction project as a "black box" and ignores the complex internal production process and stage differences. The performance measurement results of the assembly construction project are more accurate, and the quantitative evaluation of the assembly construction technology is realized. The Tobit regression model is used to calculate according to the fitted parameter values ​​and statistical values ​​to identify the main driving factors affecting the performance of the assembly construction project. The implementation results not only improve the accuracy of performance measurement, but also may provide more targeted suggestions for project managers in the selection of technical systems in the project planning stage.

[0048] This example selects 30 shear wall structure system projects as the research objects. These projects are completed using the prefabricated concrete technology system (PC) and the prefabricated reinforced block masonry technology system (PCM). Among them, DMU1-14 is built by the PC technology system, and DMU15-30 is built by the PCM technology system. Both technology systems have been accepted in accordance with relevant standards in all aspects from component production to construction, as shown in Table 1. Except for the construction technical specifications, the acceptance standards of the two technology systems are consistent, and the project quality is considered to be the same.

[0049] Table 1 Comparison of technical systems with reference to specifications and standards

[0050]

[0051] 2. Build a project performance measurement model

[0052] This study established a three-stage super-efficiency EBM model to better evaluate the performance of prefabricated construction projects. The model divides the "black box" in the traditional DEA model into three sequentially connected subsystems, which correspond to the three stages of evaluating the performance of prefabricated construction projects. The first stage is the prefabricated component production stage, which takes the resource consumption dimension required for component production as input and the output of component production as output. It mainly measures the resource utilization in the component production stage. The second stage is the transportation stage of prefabricated components after production is completed. It takes the resources required to transport the components to the site as input and the amount of components transported to the site as output. It mainly measures the resource allocation in the transportation stage. The third stage is the construction stage of transporting components to the site. It takes the resources required to complete the assembly of components transported to the site as input, and the amount of prefabricated components assembled in the project and the content of prefabricated components per square meter as output. It measures the resources required to complete the installation of the prefabricated components in the prefabricated construction project. See the schematic diagram Figure 2 .

[0053] 3. Construct a multi-input and multi-output evaluation index system

[0054] Constructing a multi-input-multi-output evaluation index system for prefabricated construction project performance The multi-input-multi-output evaluation index system includes:

[0055]

[0056] The present invention uses MAXDEA 9.0 software to solve and construct the three-stage super efficiency EBM model. As shown in Table 2, the comprehensive efficiency of 30 projects and the efficiency values ​​and rankings of the three stages are summarized.

[0057] Table 2 Performance scores and rankings of assembly construction projects

[0058]

[0059]

[0060] The results show that among the 30 DMUs, 8 prefabricated projects have performance greater than 1, with the highest efficiency value being 1.174 (DMU26) and the lowest efficiency value being 0.499 (DMU14), with a difference of 57.5%. Among the top 15 projects, 14 projects applied the PCM technology system, which shows that in the projects with prefabricated concrete shear wall structure system, the performance of prefabricated projects with PCM technology system is generally better than that of PC technology system, and the resource utilization efficiency is higher.

[0061] The three-stage super-efficiency EBM model measures the efficiency value of each stage in the project performance, so as to more clearly identify the impact of each stage on the comprehensive efficiency value of the performance of the prefabricated construction project. The results show that in the prefabricated component production stage, 9 projects have an efficiency value greater than 1, the highest efficiency value is 1.421, and the lowest efficiency value is 0.957, with a difference of 32.7%. Thirteen of the top 15 projects apply the PCM technology system. It is worth noting that the top two DMUs are PC technology systems, with efficiency values ​​of 1.421 and 1.363, which are significantly higher than the efficiency values ​​of other DMUs. In the prefabricated component transportation stage, 6 projects have an efficiency value greater than 1, the maximum efficiency value is 1.064, and the minimum efficiency value is 0.546, with a difference of 48.7%. Thirteen of the top 15 projects apply the PCM technology system. In the prefabricated component construction stage, 11 projects have an efficiency value greater than 1, of which the maximum efficiency value is 1.255 and the minimum efficiency value is 0.367, with a difference of 70.8%. The top 15 projects all applied the PCM technology system.

[0062] In general, in the prefabricated shear wall structure system project, the performance of the prefabricated construction project of the PCM technology system is significantly better than that of the PC technology system. By comparing the differences in the efficiency values ​​of the three stages in the prefabricated construction project, it is found that the prefabricated component construction stage is the main link that causes the performance of the prefabricated construction project of the PCM technology system to be better than that of the PC technology system.

[0063] 4. Extract influencing factors

[0064] The differences in production methods, transportation methods and construction methods of prefabricated components of the two technical systems were compared, and the influencing factors were extracted.

[0065] In the component production stage, it is first necessary to clarify the production process of prefabricated concrete construction technology (PC) and prefabricated reinforced block masonry construction technology (PCM). The production methods of the two technical systems are essentially different. After receiving the production task, the prefabricated concrete construction technology (PC) produces molds of different sizes in advance according to the component layout, and the production personnel carry out production on the assembly line according to their respective processes. After receiving the production task, the prefabricated reinforced block masonry technology system (PCM) first produces four standard hollow blocks, and then uses standard blocks to layout the components according to the component size. The production personnel use the unit production method to lay out the components and independently complete the production of each component. The different production methods of different technical systems lead to differences in labor costs and material costs. The PC technical system needs to customize molds to produce prefabricated components, while the PCM technical system uses four standard blocks to lay out prefabricated components, and does not need to customize molds of other sizes. This difference not only affects the utilization efficiency of production materials, but also more types of molds will affect the production efficiency of workers. In addition, the main material required for the production of prefabricated components under the PC technology system is concrete, while the main materials required for the production of prefabricated components under the PCM technology system are standard hollow blocks and concrete with a porosity of 45%. This results in different main material usage per cubic meter of components. The main material usage of prefabricated components under the PCM technology system increases by 45% compared to the PC technology system, and the main material prices are also different. Although the unit price of steel bars is the same, the difference in the amount of steel bars used will have an impact on production costs. The prefabricated components produced by the PC technology system are all "single-line" shaped, while the components produced by the PCM technology system have more styles, including "single-line", "I-type", "T-type", etc. (see comparison) Figure 3 ), the volume of a single component is quite different from that of components produced by the PC technology system, which may also affect the resource utilization efficiency in the production stage. Therefore, this paper selects the number of molds, the price of steel bars per cubic meter of components, the price of main materials per cubic meter of components, the amount of main materials per cubic meter of components, and the volume of a single component as the factors affecting the performance of prefabricated component production.

[0066] During the component transportation stage, there are obvious differences in the transportation methods of PC and PCM prefabricated components. PC prefabricated components are transported vertically or sideways, and the prefabricated components are placed in special transport racks and fixed (see Figure 4 PCM prefabricated components are self-stabilized based on their shape and do not require special transport racks for fixing. Based on this feature, they can be interspersed and placed on transport vehicles (see Figure 4The right figure) leads to a large difference in the transportation space utilization of the two technical systems during the transportation process of prefabricated components. Considering the transportation load limit, the number of components transported at a time has a significant relationship with the weight and volume of the components. Therefore, this study selects the transportation space utilization, the volume of a single component, the weight of a single cubic meter component and the weight of a single component as the influencing factors of the performance of the assembly construction project in the component transportation stage.

[0067] During the component construction stage, PC prefabricated shear wall components use the grouting sleeve connection construction process. First, the vertical steel bars reserved for inserting into the prefabricated shear wall are positioned and straightened with the straightening plate, and then aligned with the reserved channels of the prefabricated shear wall. After removing the straightening plate, the on-site pouring is carried out. The connection process of PCM prefabricated shear wall components adopts the "rebar penetration" construction process. There is no need to position the reserved steel bars. Instead, the steel bars are inserted into the guide tubes reserved in the shear wall components. After the prefabricated shear wall components are placed, the guide tubes are withdrawn and the on-site pouring is carried out. The connection methods of prefabricated shear wall components of the two technical systems are shown in Figure 5 . The connection accuracy requirement of prefabricated components affects the construction difficulty and quality, and the connection accuracy requirement of prefabricated shear wall components is caused by the difficulty of connecting the vertical steel bars with the reserved channels. Therefore, this study proposes the concept of installation tolerance, which is defined as the ratio of the allowable movement range of adjacent vertical steel bars to the size of the reserved channel. In addition, the frequency of component installation affects the difficulty of scheduling construction shifts, which affects both the construction labor cost and the construction time cost. Therefore, this paper selects the installation tolerance, the number of component installations per unit volume, and the number of component installations as factors affecting project performance during the construction phase.

[0068] Factors that affect performance:

[0069]

[0070] 5. Tobit model results

[0071] In order to identify the core influencing factors of prefabricated construction project performance, Stata17 was used to run the Tobit model to conduct an empirical analysis of 30 DMUs. The results are shown in Tables 3-5

[0072] Table 3 Results of factors affecting the production stage

[0073] Variable Name Regression coefficient Standard Deviation Statistics p-value Number of molds -0.126 0.024 -5.245 0.000 Number of components 0.004 0.013 0.318 0.751 Price of steel bars per cubic meter of component -0.199 0.029 -6.757 0.000 Price of main materials per cubic meter of components 0.587 117.52 0.005 0.996 Main material consumption per cubic meter of component -1.146 47.61 -0.024 0.981 Volume of a single component 0.138 0.041 3.32 0.001

[0074] Table 4 Results of factors affecting the transportation stage

[0075]

[0076] Table 5 Results of factors affecting the construction stage

[0077] Variable Name Regression coefficient Standard Deviation Statistics p-value Component installation quantity 0.000 0.000 -0.745 0.456 Number of component installations per unit volume -0.250 0.048 -5.165 0.000

[0078] The results show that in the prefabricated component production stage, the number of molds, the price of steel bars per cubic meter of components, and the volume of a single component passed the significance test and showed an extremely significant state (0.01≤p≤0.5), and the regression coefficients were -0.126, -0.199, and 0.138, respectively. In the prefabricated component transportation stage, the vehicle space utilization rate, the weight of a cubic meter of components, and the volume of a single component showed an extremely significant state, and the regression coefficients were 0.764, -0.253, and -0.214, respectively. In the prefabricated component construction stage, the installation fault tolerance rate and the number of installations per cubic meter of components showed an extremely significant state, and the regression coefficients were 2.660 and 0.354.

[0079] In the prefabricated component production stage, the regression coefficient of the steel bar price per cubic meter component is -0.199, which is the highest among the significant influencing factors, indicating that it has the greatest impact on the performance of prefabricated construction projects in the production stage and is negatively correlated. The regression coefficient of mold type is -0.126, indicating that the more molds there are, the lower the performance of prefabricated construction projects in the production stage. The regression coefficient of the volume of a single component is 0.138, which indicates that the larger the volume of a single component, the higher the performance of prefabricated construction projects in the production stage.

[0080] During the prefabricated component transportation stage, the maximum regression coefficient of transportation space utilization was 0.764, and it passed the significance test, which shows that transportation space utilization has the greatest impact on the performance of prefabricated construction at this stage. The regression coefficient of the weight of a cubic meter of components was -0.253, and it passed the significance test, which shows that the smaller the weight of a cubic meter of components, the higher the performance of prefabricated construction projects during the transportation stage. After comprehensively considering the space utilization rate and vehicle weight limit, the smaller the volume of a single component, the more advantageous the performance of prefabricated construction during the transportation stage (the regression coefficient is -0.214).

[0081] During the prefabricated component construction phase, the maximum regression coefficient of the installation tolerance rate is 0.905, which is the largest regression coefficient among the influencing factors in the construction phase, indicating that the installation tolerance rate has the most significant impact on the performance of prefabricated construction during the construction phase. The regression coefficient of the number of installations per unit volume is -0.250, indicating that the fewer the number of installations per unit volume, the more advantageous the performance of prefabricated construction projects during the construction phase.

[0082] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A method for evaluating the assembly construction technology system based on project performance, characterized in that: include: Step A1: Divide the prefabricated construction project into three stages, construct a multi-input-multi-output evaluation index system, and collect input and output data of different stages of the prefabricated construction project of the target structural system that has been completed according to the evaluation index system; The three stages include: prefabricated component production stage, prefabricated component transportation stage and prefabricated component construction stage; Step A2: construct a three-stage super-efficiency EBM model, and use the input and output data of the different stages combined with the three-stage super-efficiency EBM model to obtain the total performance and performance of each stage of the completed assembly construction project of the target structural system; Step A3: Analyze the overall performance and performance of each stage of the prefabricated construction projects that have been completed with the target structural system, obtain the overall performance ranking and performance ranking of each stage of the prefabricated construction projects, and conduct an overall and phased evaluation of the projects of different technical systems used in the prefabricated construction projects that have been completed with the target structural system.

2. According to claim 1, a method for evaluating an assembly construction technology system based on project performance is characterized in that: In step A1, the multi-input-multi-output evaluation indicator system includes:

3. A method for evaluating an assembly construction technology system based on project performance according to claim 1 or 2, characterized in that: In step A2, the formula of the three-stage super-efficiency EBM model is: Where r * To build project performance for assembly; i is the slack variable of the i-th input factor; j is the decision-making unit; n is the total number of DMUs; w i The importance of the input indicator is satisfied X ij and Y rj are the i-th input factor and the r-th output factor of decision-making unit j respectively; x ik and rk are the i-th input factor and the r-th output factor of decision-making unit k respectively; m and s are the number of inputs and outputs respectively; θ is the planning parameter of the radial part; λ j is the linear combination coefficient; ε x is the key parameter, satisfying 0≤ε x ≤1.

4. The method for evaluating an assembly construction technology system based on project performance according to claim 1 is characterized in that: It also includes a method for analyzing factors affecting performance, which includes: Step B1: Compare the differences in all stages of construction of all technical systems in the completed assembly construction projects, and extract the factors that affect the performance; Step B2, construct a Tobit model, use the factors that affect the performance and the performance of the completed assembly construction project at different stages described in step A2 in combination with the Tobit model to obtain the regression coefficients of the influencing factors; use the regression coefficients to obtain the degree of influence of different influencing factors on the performance at different stages.

5. The method for evaluating the assembly construction technology system based on project performance according to claim 4 is characterized in that: In step B2, the method for extracting factors that affect performance is: comparing and analyzing differences in prefabricated component production methods, prefabricated component transportation methods, and prefabricated component construction methods to obtain factors that affect performance.

6. The method for evaluating the assembly construction technology system based on project performance according to claim 5 is characterized in that: In step B2, the formula of the Tobit model is: Where Y l Represents the project performance results, x l is the quantitative index of each influencing factor, l is the decision-making unit number, β T is the regression coefficient of the influencing factor, ε l is the error term.

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