Research On Multi-Objective Optimization Of Resource-constrained Project Scheduling Based On BIM

With the rapid development of information technology,informatization plays an increasingly important role in modernization construction,which opens a new era of informatization for project scheduling management.At the same time,construction projects are developing in the direction of large-scale,diversified investment structure,advanced technology,and complex management.The role and importance of project scheduling in management is becoming increasingly prominent.As the core technology of the information development in engineering construction industry,BIM technology runs through the entire life cycle of project,and integrates various information in the entire life cycle of the project,which lays the foundation for all kinds of analysis and optimization based on BIM.Therefore,based on BIM technology theory,uncertain project scheduling theory and multi-objective optimization method,this thesis considers the uncertain factors in the actual project to optimize the cost,time and robustness of project scheduling.Firstly,use resource-constrained project scheduling theory,BIM basic theory and multiobjective optimization theory to combine multi-objective optimization of project scheduling with BIM technology.This thesis proposes an integrated optimization method of resource constrained project scheduling based on BIM,and designs an integrated optimization framework of resource constrained project scheduling integration optimization based on BIM.According to the above method,the information in the life cycle of the building information model is associated with the information required for scheduling optimization.The BIM model is used to obtain the component connection and support relationships to gain logical constraints between activities,and these are used as inputs for scheduling optimization.Secondly,for the scheduling optimization problem,this thesis focuses on the problem that the uncertainty of the time in the real environment may lead to the poor robustness of the scheduling plan.Considering that the impact of activity delay is transmitted backwards,this thesis proposes an improved robustness measurement index based on the cumulative delay risk of the activity,which takes the sum of weighted time buffers of activity cumulative delay risk as the basis to evaluate the risk resistance ability of scheduling plan.Then,a multi-objective optimization model of time cost robustness for project scheduling under the uncertainty of time is constructed.Thirdly,in view of the complexity of the three-objective optimization problem,this thesis adopts the NSGA-III algorithm based on reference points to solve the multi-objective scheduling optimization model of time-cost-robustness.Finally,in a project case,the integrated optimization method based on BIM and the multiobjective optimization model under uncertainty are applied to obtain the Pareto optimal solution set.Then according to the scheduling integration optimization framework,the optimized scheduling plan and the BIM three-dimensional model are integrated into the four-dimensional scheduling simulation model to dynamically visualize the whole process of project scheduling.Through case application,it not only verifies the feasibility and effectiveness of the proposed integrated optimization method and multi-objective optimization model,but also verifies the correctness of the designed NSGA-III algorithm.