基于挣值管理的项目进度指标的研究

Research on Project Schedule Index Based on Earned Value Management

挣值管理中的进度指标存在不合理之处,项目超期时,进度执行指标SPI含义不准确,运用公式计算的预测完工时间ETTC也不正确。通过挣值评价图进行原因分析,可对进度指标的不合理之处加以修正:当项目超期时,SPI的含义不再是进度效率,而是项目完工百分比,预测完工工期的计算公式相应地修正为ETTC=ATE/SPI。经过修正,能够进一步理解SPI的含义,对完工工期的预测也更加科学、可靠。

There are some illogical places of schedule indexes in earned value management,that is,the meaning of schedule performance index（SPI） is inaccurate and the expected time of completion（ETTC） calculated by formula is also incorrect when expeeding the schedule.Analyzing the reasons by earned value evaluation chart can modify those illogical places： when expeeding the schedule,the meaning of SPI is not schdule efficiency but project completing percentage,and the calculating method of ETTC is accordingly modified by ETTC=ATE/SPI.The modification is better to understand the meaning of SPI,and is more scientific and credible to expect the completing time.