IPD project profit distribution method based on multi-dimensional fair preference and BIM

Abstract

The invention discloses an IPD project profit distribution method based on multi-dimensional fair preference and BIM, and the method comprises the following steps: building a basic hypothesis of a model according to a Stackelberg game theory principle; constructing a model by analyzing output utility, effort cost, fair utility and risk cost of participants; introducing multi-dimensional fair preferences of participants, and determining an optimal sharing coefficient of fair preferences of each dimension in the model; and finally, analyzing by adopting a simulation method. On the basis of the Stackelberg game theory, the fair preference of participants is considered, the IPD project profit distribution model using the BIM technology under the multi-dimensional fair preference is constructed, the optimal sharing coefficient is found, while the IPD project profit distribution mechanism is perfected, reasonable project profit distribution among alliance members is promoted, team cooperation is enhanced, smooth implementation of the IPD project is promoted, and the profit distribution efficiency of the IPD project is improved. And the profitability of the project is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of project profit distribution, and in particular to an IPD project profit distribution method based on multi-dimensional fairness preference and BIM. Background Art

[0002] The integration of building information modeling (BIM) and the integrated project delivery (IPD) model has effectively promoted collaboration among project members and improved the profitability of the project. However, the problem of profit distribution significantly affects the successful implementation of IPD projects. In the context of BIM and IPD collaboration, the core idea is profit distribution and risk sharing. A successful IPD project depends on a reasonable profit distribution mechanism. However, in an IPD project, each participant is an independent economic entity whose goal is to maximize its own interests. In the interest alliance composed of IPD project members, if each participant cannot obtain a satisfactory profit share, it will affect its participation enthusiasm and eventually lead to the disintegration of the entire interest alliance. Therefore, a scientific and fair profit distribution mechanism is crucial to the normal operation of the alliance, and it is also crucial to achieve resource complementarity and profit sharing among alliance members. Therefore, a fair and reasonable interest distribution mechanism is the basis for long-term and stable cooperation among all parties in the IPD project. It is also the guarantee for the efficient completion of the IPD project and the key to the successful coupling of BIM and IPD models.

[0003] Current research mainly emphasizes the profit distribution mechanism within the manufacturing supply chain, ignoring the impact of team collaboration and BIM technology on project profit distribution under the IPD model. In addition, in related field research, most IPD model profit distribution lacks analysis from the perspective of project participants and fails to meet the needs of all participants. At the same time, in the construction of profit distribution methods and models, most studies focus on Shapley values ​​and their correction using certain profit distribution elements. However, these methods are relatively simple and lack thoroughness. Summary of the invention

[0004] The purpose of the present invention is to provide an IPD project profit distribution method based on multi-dimensional fairness preference and BIM. Combining BIM and IPD, based on Stackelberg game theory, comprehensively considering output utility, effort cost, risk aversion coefficient, fairness utility, etc., a profit distribution model is constructed, and different horizontal and vertical scenarios of the fairness preferences of the participants are introduced, and models are constructed respectively. Finally, the optimal profit distribution coefficient under each fairness preference is solved, and the development of the IPD model is promoted to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: The IPD project profit distribution method based on multi-dimensional fairness preference and BIM includes the following steps: S1: Based on the principles of Stackelberg game theory, the basic assumptions of the model were established; S2: Construct a model by analyzing the participants’ output utility, effort cost, fairness utility and risk cost; S3: Introduce participants’ multi-dimensional fairness preferences, including neutral fairness preferences, horizontal fairness preferences, and vertical fairness preferences, and determine the optimal sharing coefficient of each dimension of fairness preference in the model; S4: Use simulation method for analysis.

[0006] Furthermore, there are three basic assumptions in S1: Hypothesis 1: Considering the participants involved in the profit distribution of IPD projects as core stakeholders, the main stakeholders include owners, architects, and contractors; Hypothesis 2: Under the IPD model, the owner forms a project alliance by selecting partners. In the IPD project with a multi-party contract structure, the owner, as the initiator of the project, owns the project and is the leader of the IPD project, while the architect and contractor, as the participants of the project, are the followers of the project. The profit sharing of the IPD project is regarded as a Stackelberg game dominated by the owner. Assumption 3: The IPD model adopts a comprehensive collaborative approach, where the owner and participants share all profits of the project. At the same time, in the IPD project, the profit obtained by each member is greater than the cost invested, that is, each member obtains a certain net profit.

[0007] Furthermore, the output utility component model of participants in S2 is as follows: Suppose the output utility of participant i in the IPD project is , then it is expressed as: (1); In the IPD project, the output utility of participant i Distributed between the owner and participant i, between the owner and participant i, let the owner’s sharing coefficient be , participant i is , then among all members, the owner's sharing coefficient is , the sharing coefficient of participant i is ;set up It is a fixed reward, which is a kind of in-kind compensation for resource consumption in the project. At this time, the owner's total income and the total income S of participant i i It is expressed as: (2); (3); in, The output utility of the participants is used to measure the output of various behaviors of technical contribution and shared resource investment risk; The degree of effort of the participants, that is, the degree of effort in early participation, resource investment, and solidarity and cooperation; is the effort utility coefficient of participant i, which refers to the utility brought by unit effort; is a normally distributed variable with external random interference, with a mean of 0 and a variance of ; is the profit allocation coefficient obtained by participant i.

[0008] Furthermore, the effort cost component model of participants in S2 is as follows: The effort cost of participant i is measured by the effort level and effort cost coefficient ,get , >0; where is the effort cost coefficient of participant i, which refers to the cost per unit of effort, The larger the value, the higher the unit effort cost of the participant, that is, the effort cost of participant i The degree of effort is proportional to Is the degree of effort An increasing function, so i, > 0; in addition, the marginal cost of effort is also increasing, i.e. > 0; therefore, the effort cost of player i is set to: (4).

[0009] Furthermore, the fair utility component model of participants in S2 is as follows: Building a fair utility function : (5); in, ( > 0), ( > 0) is the horizontal or vertical pride preference intensity and jealousy preference intensity, that is, the degree of perception of fairness; S i , S j is the total income of participants i and j; For the convenience of calculation, in formula (5) , then the fair utility of participant i is: (6).

[0010] Furthermore, the risk cost component model of participants in S2 is as follows: Assume that the actual utilities of the owner and the participant are U and V respectively i , represents the net profit without considering the risk cost; according to the total profit S of the owner j , the total benefit S of the participants i , Effort Cost and fair utility i , the actual utilities U and V of the owner and participant can be calculated i They are: (7); (8); The risk cost of participant i is described as ,in, is the risk aversion coefficient of the participant, i.e., the degree of risk aversion; r i (r i ≥0) is the risk aversion measure of participant i, i.e., the risk aversion coefficient, r i The larger the value, the higher the risk aversion; D(V i ) represents the actual utility V of participant i i The variance of the risk cost of the participants can be obtained from equations (3), (4), and (8): The specific expression is: (9); in, Represents the standard deviation of the normal distribution followed by the external random disturbance variable; From the above, we can see that the certainty equivalent utility of owners and participants in IPD projects is , It is expressed as: (10); (11).

[0011] Furthermore, the neutral fairness preference model in S3 is constructed as follows: When participant i has a neutral fairness preference, his actual utility V wi for (12); get, Then it is the owner's deterministic equivalent utility u w and the deterministic equivalent utility v of participant i wi (13); (14); In the IPD project, in order to ensure that the expected utility of each participant is not less than the utility obtained without participating in the project, the owner assumes that the profit that participant i can still obtain without participating in the project is W. i ,but: (15); Right now: (16); When the fairness preference of the participants is neutral, taking equation (16) as a constraint, the profit distribution model of the IPD project is: (17); Substitute the participation constraint into the objective function, derive the sharing coefficient, and obtain the optimal profit distribution coefficient of participant i from the first-order optimal condition and optimal effort level ; (18).

[0012] Furthermore, the horizontal fairness preference model in S3 is constructed as follows: According to formula (7), when the horizontal fairness strength of participant i is , horizontal fairness preference utility as follows: (19); In this case, the actual utility of participant i is: (20); at this time, , , the owner's utility equivalent to certainty and the participant's utility equivalent to certainty v hi , we can get the following formula: (twenty one) ; (twenty two); When participants have a horizontal fairness preference, >W i and max(v hi ), the profit distribution model of the IPD project is as follows: (twenty three); By substituting the participation constraint into the objective function, the sharing coefficient is derived, and the optimal profit sharing coefficient is obtained from the first-order optimality condition. and the optimal effort level a hi for: (twenty four).

[0013] Furthermore, the vertical fairness preference model in S3 is constructed as follows: Let p zi represents the strength of vertical fairness preference, and the utility e brought by vertical fairness preference zi as follows: (25); The actual utility of participant i is: (26); At this point, the deterministic equivalent utilities of owners and participants are as follows: (27) ; (28); When a participant has a vertical fairness preference, and max(v zi ) is a constraint condition, the profit distribution model of the IPD project is as follows: (29); Substitute the constraints into the objective function, derive the profit distribution coefficient, and obtain the optimal profit distribution coefficient and effort level through the first-order optimization condition: (30).

[0014] Furthermore, the specific method in S4 is: using the control variable simulation method to analyze the participants' effort cost coefficient k, effort utility value , the effect of fairness preference intensity P on output utility I, and profit distribution coefficient , the impact of total revenue S.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The IPD project profit distribution method based on multi-dimensional fairness preference and BIM provided by the present invention is based on Stackelberg game theory, takes into account the fairness preference of participants, constructs an IPD project profit distribution model using BIM technology under multi-dimensional fairness preference, and finds the optimal sharing coefficient. While improving the IPD project profit distribution mechanism, it promotes the reasonable distribution of project profits among alliance members, enhances team collaboration, promotes the smooth implementation of IPD projects, and improves the profitability of projects. DETAILED DESCRIPTION

[0016] The embodiments of the present invention will be described in detail below, however, the embodiments of the present invention are not limited thereto. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] The IPD project profit distribution method based on multi-dimensional fairness preference and BIM provided by the embodiment of the present invention comprises the following steps: Step 1: Based on the principles of Stackelberg game theory, the basic assumptions of the model are established; Stackelberg game is a strategic game model in game theory that emphasizes the impact of information asymmetry and sequential decision-making on game outcomes. In the Stackelberg game model, two distinct groups, "leaders" and "followers", coexist, both of which aim to maximize their personal interests. Leaders make decisions in advance, and followers make decisions based on the leader's choices. Therefore, leaders can influence followers by making strategic choices to achieve the maximum benefit of the project; based on this, there are three basic assumptions in this step: Hypothesis 1: The main team members of the IPD model usually include owners, architects, general contractors and other stakeholders. In addition, early participants who have a significant impact on project design and cost are considered to be the most valuable. Therefore, participants who participate in the profit distribution of IPD projects are considered as core stakeholders. The main stakeholders include owners, architects and contractors. Hypothesis 2: Under the integrated project delivery (IPD) model, the owner forms a project alliance by selecting partners. Usually, the owner, architect and general contractor will sign a multi-party agreement, and other parties (such as consultants, suppliers, etc.) will sign subcontract agreements with the above three parties. Therefore, in IPD projects with a multi-party contract structure, the owner, as the initiator of the project, owns the ownership of the project and has a high degree of control power. He is often the leader of the IPD project, while the architect and contractor, as the participants of the project, are often the followers of the project. Therefore, the profit sharing of the IPD project can be regarded as a Stackelberg game dominated by the owner. Hypothesis 3: The IPD model adopts a comprehensive collaborative approach to improve project returns by optimizing efficiency, reducing costs, improving quality, and effectively managing risks. In addition, the IPD model emphasizes risk and benefit sharing to ensure unified collaboration among all stakeholders. Therefore, the owner and participants share all profits of the project. At the same time, in the IPD project, the profit obtained by each member is greater than the cost invested, that is, each member obtains a certain net profit.

[0018] Step 2: Build a model by analyzing the output utility, effort cost, equity utility and risk cost of the participants. Specifically, in the multi-party contract of the integrated project delivery (IPD) model, the project parties will jointly agree on the project's goals and scope, the roles and responsibilities of the participants, the risk and return sharing, the profit distribution mechanism, etc., to ensure the cooperation, coordination and orderly progress of the project. "Risk sharing and benefit sharing" is one of the core principles of the IPD project alliance contract design. In the process of profit distribution, adhering to the principles of "profit and risk symmetry", "input and return balance" and "fair distribution" can promote the stable operation of the cooperative alliance. Among them, the model symbols and variable definitions are shown in Table 1: Table 1 Symbols and variable definitions ; ; Specifically, the output utility component model of the participants is as follows: In the IPD project, architects use BIM technology to coordinate and integrate multiple units and multiple trades. Owners and contractors use the BIM platform provided by architects to communicate and exchange information, which greatly promotes the collaboration of all parties, reduces the waste of project resources, and increases project benefits. Due to the nature of the project, contractual agreements, and the diversity of roles and contributions of all parties, there are various ways to share the profits of the entire project. Some parts may not be shared (such as proprietary rights), while some parts may benefit equally among all parties (such as shared profits of resources such as equipment and technical platforms). In addition, different distribution methods can be adopted for some parts (for example, based on technical contribution, resource input, and goal achievement). Since the degree of technical contribution, the amount of resource input, and the degree of goal achievement are determined by the optimal output of the participants, the optimal output of the participants can be used to measure the profits in this regard. At the same time, the optimal output of all parties in the project is a one-dimensional variable that is positively correlated with the degree of effort. Secondly, during the implementation of the IPD project, the output utility of the participants is related to their degree of effort (including early participation enthusiasm, risk sharing, mutual cooperation, etc.), as well as their effort utility value and exogenous uncertainty. Based on this, let the output utility of participant i in the IPD project be , then it is expressed as: (1); In the IPD project, the output utility of participant i Distributed between the owner and participant i, between the owner and participant i, let the owner’s sharing coefficient be , participant i is , then among all members, the owner's sharing coefficient is , the sharing coefficient of participant i is ;set up It is a fixed reward, which is a kind of in-kind compensation for resource consumption in the project. At this time, the owner's total income and the total income S of participant i i It is expressed as: (2); (3).

[0019] Furthermore, the effort cost component model of the participants is as follows: In the IPD project, each participant needs to pay a corresponding effort cost to promote the development of the project. Although the effort cost of the participants is not easy to measure directly, the effort cost and the effort cost coefficient are quadratically related. Therefore, the effort cost of participant i is measured by the effort level and the effort cost coefficient. ,get , > 0; where is the effort cost coefficient of participant i, The larger the value, the higher the unit effort cost paid by the participant, which can be obtained through evaluation or experience, that is, the effort cost of participant i The degree of effort is proportional to Is the degree of effort is an increasing function, so i, > 0; in addition, the marginal cost of effort is also increasing, i.e. > 0; therefore, the effort cost of player i is set to: (4).

[0020] Furthermore, the fair utility component model of the participants is as follows: Fairness preference is a psychological behavior of participants regarding whether the distribution of their benefits is fair. Fairness preference means that participants care not only about their own profits, but also about the profits of other members, and the difference between profits will also affect the total utility. According to the classic FS model, if a person gains less than others, he will produce additional negative utility due to jealousy, which is called negative jealousy utility; if a person gains more than others, he will produce additional negative utility due to guilt, which is called negative guilt utility. Based on this, a fair utility function is established. It can be expressed by FS model: (5); in, ( > 0), ( > 0) is the horizontal or vertical pride preference intensity and jealousy preference intensity, that is, the degree of perception of fairness; S i , S j is the total income of participants i and j; For the convenience of calculation, in formula (5) , then the fair utility of participant i is: (6).

[0021] Furthermore, the risk cost component model of the participants is as follows: There are certain risks in the implementation of IPD projects, including collaboration risks, technical risks, natural risks, political and legal risks, market risks, and economic risks. Owners are usually risk-neutral, while participants are usually risk-averse. Therefore, participants will take corresponding measures to reduce risks and incur risk costs. Assume that the actual utilities of the owner and the participant are U and V respectively i , represents the net profit without considering the risk cost; according to the total profit S of the owner j , the total benefit S of the participants i , Effort Cost and fair utility i , the actual utilities U and V of the owner and participant can be calculated i They are: (7); (8); The risk cost of participant i is described as ,in, is the risk aversion coefficient of the participant, i.e., the degree of risk aversion; r i (r i ≥0) is the risk aversion measure of participant i, i.e., the risk aversion coefficient, r i The larger the value, the higher the risk aversion; D(V i ) represents the actual utility V of participant i i The variance of the risk cost of the participants can be obtained from equations (3), (4), and (8): The specific expression is: (9); in, Represents the standard deviation of the normal distribution followed by the external random disturbance variable; From the above, we can see that the certainty equivalent utility of owners and participants in IPD projects is , It is expressed as: (10); (11).

[0022] Step 3: Introduce the multi-dimensional fairness preferences of the participants, including neutral fairness preferences, horizontal fairness preferences and vertical fairness preferences, and determine the optimal sharing coefficients of each dimension of fairness preferences in the model; specifically, in the owner-dominated Stackelberg game, the owner dominates the decision on the profit distribution coefficient; then, the participants adjust their personal effort levels according to these decisions to achieve the best response. Therefore, the owner's total income function is the objective function of the model, and the participant's optimal response function a(b) is the constraint. At the same time, the inverse solution method is combined with the participants' multi-dimensional fairness preferences to obtain the optimal profit distribution coefficient and effort level of the model under each fairness preference dimension. Furthermore, the neutral fairness preference model is constructed as follows: When participant i has a neutral fairness preference, his actual utility V wi for (12); get, Then it is the owner's deterministic equivalent utility u w and the deterministic equivalent utility v of participant i wi (13); (14); In the IPD project, in order to ensure that the expected utility of each participant is not less than the utility obtained without participating in the project, the owner assumes that the profit that participant i can still obtain without participating in the project is W. i ,but: (15); Right now: (16); In summary, when the fairness preference of the participants is neutral, taking formula (16) as a constraint condition, the profit distribution model of the IPD project can be obtained as: (17); Substitute the participation constraint into the objective function, derive the sharing coefficient, and obtain the optimal profit distribution coefficient of participant i from the first-order optimal condition and optimal effort level ; (18).

[0023] Furthermore, the horizontal fairness preference model is constructed as follows: Horizontal means that participants care not only about their own interests, but also about the interests of other participants. The differences between these interests will also affect their total utility. According to formula (7), when the horizontal fairness intensity of participant i is , horizontal fairness preference utility as follows: (19); In this case, the actual utility of participant i is: (20); so, , , the owner's utility equivalent to certainty and the participant's utility equivalent to certainty v hi , we can get the following formula: (twenty one) ; (twenty two); Therefore, when a participant has a horizontal fairness preference, satisfying >W i and max(v hi ), the profit distribution model of the IPD project is as follows: (twenty three); By substituting the participation constraint into the objective function, the sharing coefficient is derived, and the optimal profit sharing coefficient is obtained from the first-order optimality condition. and the optimal effort level a hi for: (twenty four).

[0024] Furthermore, the vertical fairness preference model is constructed as follows: Vertical means that participants will compare their own profits with the owner, and the difference in these profits will also affect the total utility of the system; similar to the horizontal fairness preference, the vertical pride preference and the vertical envy preference are considered simultaneously; let p zi represents the strength of vertical fairness preference, and the utility e brought by vertical fairness preference zi as follows: (25); The actual utility of participant i is: (26); At this point, the deterministic equivalent utilities of owners and participants are as follows: (27) ; (28); Therefore, when a participant has a vertical fairness preference, and max(v zi ) is a constraint condition, the profit distribution model of the IPD project is as follows: (29); Substitute the constraints into the objective function, derive the profit distribution coefficient, and obtain the optimal profit distribution coefficient and effort level through the first-order optimization condition: (30).

[0025] Step 4: Use simulation method for analysis: In IPD projects, collaborative entities jointly form a cooperative alliance to meet the requirements of the owner and ensure the successful delivery of project functions or values. However, as different economic entities, these stakeholders must also consider the maximization of their personal total returns. According to the above model, the total income of the participants is closely related to the output utility and the shared benefit coefficient obtained; in IPD projects, the output utility of the participants directly affects the overall performance of the team and the cumulative benefits of the project, and may even affect the overall success of the project; the profit distribution coefficient includes multiple dimensions such as balancing the contributions of all parties, ensuring fairness, incentivizing participation, and allocating risks; it is a key factor in establishing a mutually beneficial sharing mechanism. Therefore, the output utility, profit distribution coefficient and total income of the participants can be used as dependent variables to study the sharing mechanism; through simulation, the impact of other parameters on them can be studied.

[0026] In order to maximize the benefits of the project alliance, all participants must make necessary compromises and contributions. Since each participant represents a heterogeneous enterprise with different roles and core competitive advantages, the unit effort cost and value may be different. Due to these differences, the contribution to the project is different. In addition, the profit distribution follows the principle of "high risk, high return". Due to the different risk aversion coefficients of different participating entities, the degree of risk aversion is also different. At the same time, fairness preference, as a perceptual behavior of fair benefit distribution, affects the effort level of IPD project participants and plays a vital role in the success of the project.

[0027] Based on this, this embodiment adopts the control variable simulation method to analyze the participants' effort cost coefficient k, effort utility value , key parameters such as fairness preference intensity P and output utility I, profit distribution coefficient , the impact of total revenue S.

[0028] Combining the case study of the IPD model with the risk aversion coefficient and risk standard deviation as well as the effort cost coefficient and effort utility value, for the IPD project, the main members include the owner, architect and contractor, and the specific parameter values ​​are shown in Table 2: Table 2 Related parameters ; Calculate the output utility I, profit distribution coefficient b and total income S respectively, as shown in Table 3: Table 3 Calculation results ; As can be seen from Table 2, under the multi-dimensional fairness preferences of the participants, the corresponding output utility I and profit distribution coefficient It is different from the total income S. This is because the sources of fairness perception in each dimension are different, which brings different fairness utility functions e to the participants. Therefore, the actual utility functions are different, and the optimal sharing coefficients obtained are also different. In the IPD project, all participants form an intricate and closely connected interest alliance.

[0029] In summary: the IPD project profit distribution method based on multi-dimensional fairness preference and BIM provided by the present invention, in the IPD project profit distribution mechanism using BIM technology, the owner should attach great importance to the fair preference behavior of the participants, alleviate the fierce competition brought about by horizontal fair preferences, and stimulate the efforts to solve the low initiative brought about by vertical fair preferences. Secondly, the owner should provide considerable shared profits to the participants who improve the unit utility value, contribute to improving the overall benefits of the project, and bear higher project risks, so as to motivate them to achieve project goals; the fairness preference intensity of the participants should correspond to their own situation and the actual situation of the team. At the same time, the participants should strive to enhance their risk resistance, take the initiative to bear project risks, and strive to improve the unit effort utility value while reducing costs. While fulfilling their contractual obligations, the participants should aim to improve the interests of the entire project team, increase their own profits, and promote the realization of the functions or values ​​of the IPD project.

[0030] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM is characterized by: The following steps are involved: S1: Based on the principles of Stackelberg game theory, the basic assumptions of the model were established; S2: Construct a model by analyzing the participants’ output utility, effort cost, fairness utility and risk cost; S3: Introduce participants’ multi-dimensional fairness preferences, including neutral fairness preferences, horizontal fairness preferences, and vertical fairness preferences, and determine the optimal sharing coefficient of each dimension of fairness preference in the model; S4: Use simulation method for analysis.

2. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 1, characterized in that: There are three basic assumptions in S1: Hypothesis 1: Considering the participants involved in the profit distribution of IPD projects as core stakeholders, the main stakeholders include owners, architects, and contractors; Hypothesis 2: Under the IPD model, the owner forms a project alliance by selecting partners. In the IPD project with a multi-party contract structure, the owner, as the initiator of the project, owns the project and is the leader of the IPD project, while the architect and contractor, as the participants of the project, are the followers of the project. The profit sharing of the IPD project is regarded as a Stackelberg game dominated by the owner. Assumption 3: The IPD model adopts a comprehensive collaborative approach, where the owner and participants share all profits of the project. At the same time, in the IPD project, the profit obtained by each member is greater than the cost invested, that is, each member obtains a certain net profit.

3. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 2, characterized in that: The output utility component model of participants in S2 is as follows: Suppose the output utility of participant i in the IPD project is , then it is expressed as: （1）； In the IPD project, the output utility of participant i Distributed between the owner and participant i, between the owner and participant i, let the owner’s sharing coefficient be , participant i is , then among all members, the owner's sharing coefficient is , the sharing coefficient of participant i is ;set up It is a fixed reward, which is a kind of in-kind compensation for resource consumption in the project. At this time, the owner's total income and the total income S of participant i i It is expressed as: （2）； （3）； in, The output utility of the participants is used to measure the output of various behaviors of technical contribution and shared resource investment risk; The degree of effort of the participants, that is, the degree of effort in early participation, resource investment, and solidarity and cooperation; is the effort utility coefficient of participant i, which refers to the utility brought by unit effort; is a normally distributed variable with external random interference, with a mean of 0 and a variance of ; is the profit allocation coefficient obtained by participant i.

4. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 3, characterized in that: The effort cost component model of participants in S2 is as follows: The effort cost of participant i is measured by the effort level and effort cost coefficient ,get , > 0; where is the effort cost coefficient of participant i, which refers to the cost per unit of effort, The larger the value, the higher the unit effort cost of the participant, that is, the effort cost of participant i The degree of effort is proportional to Is the degree of effort An increasing function, so i, > 0; in addition, the marginal cost of effort is also increasing, i.e. > 0; therefore, the effort cost of player i is set to: （4）。 5. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 4, characterized in that: The fair utility component model of participants in S2 is as follows: Building a fair utility function : (5); in, ( > 0), ( > 0) is the horizontal or vertical pride preference intensity and jealousy preference intensity, that is, the degree of perception of fairness; S i , S j is the total income of participants i and j; For the convenience of calculation, in formula (5) , then the fair utility of participant i is: （6）。 6. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 5, characterized in that: The risk cost component model of participants in S2 is as follows: Assume that the actual utilities of the owner and the participant are U and V respectively i , represents the net profit without considering the risk cost; according to the total profit S of the owner j , the total benefit of participants S i , Effort Cost and fair utility i , the actual utilities U and V of the owner and participant can be calculated i They are: （7）； （8）； The risk cost of participant i is described as ,in, is the risk aversion coefficient of the participant, i.e., the degree of risk aversion; r i (r i ≥0) is the risk aversion measure of participant i, i.e., the risk aversion coefficient, r i The larger the value, the higher the risk aversion; D(V i ) represents the actual utility V of participant i i The variance of the risk cost of the participants can be obtained from equations (3), (4), and (8): The specific expression is: （9）； in, Represents the standard deviation of the normal distribution followed by the external random disturbance variable; From the above, we can see that the certainty equivalent utility of owners and participants in IPD projects is , It is expressed as: （10）； （11）。 7. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 6, characterized in that: The neutral fairness preference model in S3 is constructed as follows: When participant i has a neutral fairness preference, his actual utility V wi for （12）； get, Then it is the owner's deterministic equivalent utility u w and the deterministic equivalent utility v of participant i wi （13）； （14）； In the IPD project, in order to ensure that the expected utility of each participant is not less than the utility obtained without participating in the project, the owner assumes that the profit that participant i can still obtain without participating in the project is W. i ,but: （15）； Right now: （16）； When the fairness preference of the participants is neutral, taking equation (16) as a constraint, the profit distribution model of the IPD project is: (17)； Substitute the participation constraint into the objective function, derive the sharing coefficient, and obtain the optimal profit distribution coefficient of participant i from the first-order optimal condition and optimal effort level ; (18)。 8. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 7, characterized in that: The horizontal fairness preference model in S3 is constructed as follows: According to formula (7), when the horizontal fairness strength of participant i is , horizontal fairness preference utility as follows: (19)； In this case, the actual utility of participant i is: (20)； at this time, , , the owner's utility equivalent to certainty and the participant's utility equivalent to certainty v hi , we can get the following formula: (21) ； (22)； When participants have a horizontal fairness preference, >W i and max(v hi ), the profit distribution model of the IPD project is as follows: (23)； By substituting the participation constraint into the objective function, the sharing coefficient is derived, and the optimal profit sharing coefficient is obtained from the first-order optimality condition. and the optimal effort level a hi for: (24)。 9. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 8, characterized in that: The vertical fairness preference model construction method in S3 is as follows: Let p zi represents the strength of vertical fairness preference, and the utility e brought by vertical fairness preference zi as follows: (25)； The actual utility of participant i is: (26)； At this point, the deterministic equivalent utilities of owners and participants are as follows: (27) ； (28)； When a participant has a vertical fairness preference, and max(v zi ) is a constraint condition, the profit distribution model of the IPD project is as follows: (29)； Substitute the constraints into the objective function, derive the profit distribution coefficient, and obtain the optimal profit distribution coefficient and effort level through the first-order optimization condition: (30)。 10. The IPD project profit distribution method based on multi-dimensional fairness preference and BIM as claimed in claim 9, characterized in that: The specific method in S4 is: using the control variable simulation method to analyze the participants' effort cost coefficient k and effort utility value , the effect of fairness preference intensity P on output utility I, and profit distribution coefficient , the impact of total revenue S.

Images