基于Monte Carlo仿真的随机S曲线研究

PB-S曲线是随项目进展变化的累计预算成本曲线和累计工期曲线,它综合考察了成本、工期和项目进展百分比三个变量之间的关系.SS曲线提供了与各个项目进展百分比对应的累计预算成本和累计工期的概率分布.采用Monte Carlo仿真和统计分析方法,结合一个费用和时间随机分布的网络计划,详细研究了PB-S曲线和SS曲线的仿真建模和统计分析过程.进一步,基于SS曲线,考察了费用偏差和进度偏差的统计特征,为项目绩效的预测和监测提供更详细的偏差信息.同时针对均值曲线作为基准计划曲线的局限性,提出了两种新方法用于选择一定置信度要求的PB-S曲线作为项目的基准计划曲线.

Research on Stochastic S Curves Based on Monte Carlo Simulation Analysis Technique

Progress-based S curves (PB-S curves) are defined as plots of cumulative budget and planned duration against project progress, they have the advantage of representing the three units required to follow integrated project performance, i. e. cost, time, and work progress. Stochastic S curves (SS curves) are defined as the resulting set of PB-S curves, they provide probability distributions for the budget and time values required to complete the project at any specific percentage of work completed. Using Monte Carlo simulation approach and statistical analysis method, the simulation modeling and statistical analyzing process were proposed and applied to an example project. Moreover, based on SS curves, the statistic characteristics of cost variance and schedule variance were considered, more information about cost variance and schedule variance was provided for the forecasting and monitoring of probabilistic project performance. To address the limits of selecting the average PB-S curve as the planning curve, two new methods were developed for selecting a PB-S curve with some confidence percentile level as the planning curve.