Study On Time-cost Trade-off Of Project Based On The Improved Harmony Search Algorithm

With the rapid development of China’s economy and the progress of engineering technology,the modern engineering projects have become more and more large and complicated.The risk of project delay,cost overruns and quality disqualification is becoming more and more serious.Therefore,how to achieve the best goal of project is particularly important.In the actual project management,it is usually in the premise of guaranteeing the quality that the optimal construction period of the project is met with the least cost,which is to realize the optimization of the construction period and cost.Time-cost trade-off is a typical NP-hard multio-bjective optimization problem and there are many ways to solve this problem.The traditional mathematical method and the simple heuristic algorithm lack the preciseness and efficiency,a new intelligent optimization algorithm is introduced in this paper,that is harmony search algorithm.Based on the research and improvement of the algorithm,an improved harmony search algorithm is proposed to solve the time-cost trade-off of engineering projects.The main research work of this paper is as follows:(1)This paper expounds the concept,influencing factors and calculation methods of construction project duration and cost;Based on the in-depth study of multi-objective optimization theory,many examples are given to analyze the conflict between multiple targets.It provides a theoretical basis for the establishment of the construction time-cost trade-off model.(2)Based on the critical path method in the network graph,the objective function of the time limit is established.after a detailed analysis of the relationship between direct cost and indirect cost and time limit,a cost objective function model is established.then according to the main target method,a comprehensive time-cost trade-off model of the engineering project is established and the traditional solution method of the time-cost trade-off model is summarized and analyzed.(3)Based on the harmony search algorithm principle,key elements,calculation process and the inadequacies of the elaboration and analysis,from the harmony search algorithm、the generation of initial harmony memory library、the setting of parameters and the generation of new solutions point of view,the algorithm is improved and an improved harmony search algorithm is proposed in this paper.The improved harmony search algorithm improves the quality of understanding,increases the optimization speedof the algorithm,guarantees the global convergence and avoiding the local optimum.(4)In engineering example of this paper,harmony search algorithm and improved harmony search algorithm are used to solve the problem at the same time and the optimization results are compared with the genetic algorithm.The result shows that the improved harmony search algorithm has good accuracy and reliability in the time-cost trade-off of engineering projects.