Research On Buffer Management Of Critical Chain Projects From The Perspective Of HeXie Management

Due to the the complexity of environment and uncertainty of the project,project delays and cost overruns occur frequently.Therefore,taking into account the subjective and objective uncertainties of the project,Goldratt combines the constraint theory to optimize the classic project management methods,and proposes the critical chain project management(CCPM)method.CCPM absorbs the impact of uncertain factors on project management performance with buffers,which can effectively overcome the student syndrome and Parkinson’s Law of personnel.The core of CCPM is buffer management,which mainly includes buffer determination and buffer monitoring.Buffer determination is the basis of buffer monitoring.However,the performance of the buffer management of critical chain projects is affected by the characteristics of the project itself and the manager of each activity.To reduce the uncertainty of the project and ensure the accuracy of the results,building an effective buffer determination and buffer monitoring model based on the dual characteristics of the project manager in the project planning and implementation stages should be seen as a key problem to be solved in the buffer management research.Namely,it is particularly important to manage the buffer of critical chain projects.As a corollary,to improve the comprehensive performance of buffer management of critical chain projects,this research optimizes the factors from the aspects of He and Xie respectively based on the research framework of HeXie management theory.Then,we construct and verify the corresponding models based on the results of factors optimization.The main research works are as follows:(1)From the perspective of HeXie management,the factors influencing the buffer determination are analyzed and optimized from the aspects of He and Xie.This study uses the idea of HeXie to analyze the buffer determination elements from the two aspects of the elements of the He principle and Xie principle innovatively.Namely,the reward and punishment perception of the activity manager is the element of the He principle.Then,the importance of the activity structure is the element of the Xie principle.Both not only can ensure the accuracy of the element results through reasonable measurement and analysis of the two elements,but also can reduce the impact of uncertainty of buffer determination elements on project buffer determination,which make up the limitation that the existing research does not give enough consideration to the buffer determination elements driven by the He principle.Specifically,for the factor of He principle,the prospect theory of triple reference dependency is used to calculate the comprehensive value function and decision-making weight function of each activity manager.Then the comprehensive prospect values of each activity manager at different completion times of the activity are determined.For factor of Xie principle,the network cohesions of the activity node network and the side network are calculated respectively.The improved node contraction method is applied to measure the importance of the comprehensive structure of activities.The results provide the basis for the next step of extracting the safety time of each activity and determining the buffer.(2)Based on the optimization results of buffer determination elements,a model for determining the buffer that comprehensively considers reward and punishment and importance of the activity structure with HeXie coupling is constructed.According to the perceived elements of reward and punishment and the measurement results of the importance of the activity structure,the activity safety time is extracted by comprehensively considering the factors of He and Xie.Then,a buffer determination model is built.This model not only reduces the uncertainty of the activity manager subjectively,but also considers the impact of the uncertainty of the importance of the activity structure on the buffer determination objectively.It can avoid the student syndrome of the activity manager and wasting the safety time of the activity.The simulation results of the buffer determination model show that compared with other methods,the project buffer size determined by the proposed method is more reasonable.At the same time,the comprehensive performance in terms of project duration and project cost is better,which can be specifically explained that a reasonable project buffer can better deal with the subjective and objective uncertainty or risks of the critical chain project.And the unnecessary time and cost overruns are reduced.(3)From the perspective of HeXie management,the influencing factors of buffer monitoring are analyzed from the aspects of He and Xie.For the activities of the project,trust factor between the activity manager and project manager has not been included in the scope of the existing buffer monitoring influencing factors.As an important basis to promote flexible monitoring,trust can help the project manager improve the buffer monitoring efficiency.In this research,the node trust model is used to measure the trust of activity managers from both direct trust and indirect trust.Then,we combine with the weight coefficient to calculate the comprehensive trust level of each activity manager.At the same time,from the perspective of the project,the buffer monitoring should also consider the objective uncertainties of the external environment of the project,such as the Xie priciple element such as brittleness risk.This research uses the niche width and niche overlap in the niche theory to comprehensively calculate the brittleness risk of the project.The research results of the two elements are the basis for building the buffer monitoring model.(4)Based on the analysis of the impact factors of buffer monitoring and the research results of buffer determination,a HeXie coupling buffer differential monitoring model considering the trust and brittleness risk is constructed.First,according to the measurement optimization results of the factors of HeXie buffer monitoring and buffer determination,the corresponding allocation proportions and the initial reference amount of buffer monitoring are determined.Second,to make up for the shortcomings of the original unified buffer monitoring mode,the buffer monitoring mode is divided into fault tolerant buffer monitoring and punitive buffer monitoring by considering the trust differences between the activity managers and project manager.Then,the buffer fault tolerance buffer and buffer punishment buffer are determined.Different trigger points of buffer monitoring are set respectively.Finally,we monitor the allocated buffer from the dimensions of He and Xie.Different buffer monitoring strategies are adopted for different activities based on the heterogeneity of each activity.Accordingly,the buffer configuration and trigger point position are adjusted in real time by combinating with buffer consumption.The simulation results show that the proposed buffer monitoring method can effectively reduce the error warning frequency of buffer consumption and avoid the unnecessary correction measures.Compared with other methods,the proposed method has achieved different degrees of optimization in buffer consumption rate,on-time completion rate,and other indicators.To improve the comprehensive performance of the project,this research takes the buffer management of critical chain projects as the research object and uses the research framework of HeXie management theory and other quantitative measurement methods for reference.A more adaptive buffer determination and buffer monitoring model through HeXie coupling based on the optimization analysis of He priciple factors and Xie priciple factors are constructed.The method in this research has been proved to improve the comprehensive performance of buffer management effectively,which is specifically reflected in determining more reasonable project buffer and building a more personalized buffer monitoring strategy.The research can enhance the accuracy of buffer management and reduce the wrong warning and buffer consumption,which ensure the timely completion of the project and enrich the research results of critical chain project buffer management.Innovation in research perspectives is achieved.This article applies the theory of HeXie management to the field of critical chain project management,which deepens and expands the theoretical system of HeXie management theory in buffer management research.In practice,this study can help project decision-makers to reduce the impact of subjective and objective uncertainties on project management performance and improve project management level to meet the actual needs of buffer management.