【摘要】 在项目活动时间三次估算公式的基础上,根据活动时间分布,试图减少一个极端值的估算,得出两次估算方法,以此降低时间估算中的主观性和时间估算的次数,并对两种方法推导出项目活动时间均值和方差的计算路径,同时构造了样本假设检验的方法,在试验的基础上对两种估算进行比较,从而判断和改善项目活动时间估算的适用性。最后通过实证得出当偏差系数小于-0.4或大于0.2时,活动时间估算采用三次比较适宜;当偏差系数位于二者之间时,采用二次估算比较适宜。更多还原

【Abstract】 In order to reduce one time of estimating extremum and debase subjectivity of estimating activity duration according to activity time distribution,this paper educes the method of two times estimating activity duration on the base of three times estimating formula.Calculating route of project activity time mean and variance is deduced for two kinds of method,and sample hypothesis test method is constructed.It is used to judge and improve the applicability of estimating project activity duration.Finally,based on the experimentation,the paper elicits,it is fitting to use three times of estimating activity duration while the skewness is less than-0.4 or greater than 0.2;it is feasible to reduce one time of estimating extremum.更多还原