Research on Improved PERT Model in Analysis of Schedule Risk of Project

PERT (program evaluation and review technique) is one of the most popular means in Project Time Management, however, it exists some shortcomings. Based on the assumptions of PERT, this paper illustrates the disadvantages of the normal three times estimation method and gives countermeasures to solve these problems. Firstly, it adopts the Monroe method to improve the normal ß distribution. Secondly, it improves the accuracy of the normal method of three times estimation by adopting the restrictive probability to estimate the three times and the minimal deviation model. Thirdly, it considers the effects of the secondarily crucial line. Consequently, the paper applies a new model to analyze schedule risk of project and divides it into five different grades.