EAC typical formula

Which is a correct typical EAC formula:

1) EAC =AC+(BAC-EV) / CPI

or

2) EAC =AC+(BAC-EV) / CPI*SPI

 

http://www.scribd.com/doc/28680971/101-PMP-Sample-Questions-for-the-PMP-Exam

question 81

 

This is as per PMBOK 

 Only three of the more common methods are described as follows:

  • EAC forecast for ETC work performed at the budgeted rate. This EAC method accepts the actual project performance to date (whether favorable or unfavorable) as represented by the actual costs, and predicts that all future ETC work will be accomplished at the budgeted rate. When actual performance is unfavorable, the assumption that future performance will improve should be accepted only when supported by project risk analysis. Equation: EAC = AC + (BAC – EV)

  • EAC forecast for ETC work performed at the present CPI. This method assumes what the project has experienced to date can be expected to continue in the future. The ETC work is assumed to be performed at the same cumulative cost performance index (CPI) as that incurred by the project to date. Equation: EAC = BAC / CPI

  • EAC forecast for ETC work considering both SPI and CPI factors. In this forecast, the ETC work will be performed at an efficiency rate that considers both the cost and schedule performance indices. This method is most useful when the project schedule is a factor impacting the ETC effort. Variations of this method weight the CPI and SPI at different values (e.g., 80/20, 50/50, or some other ratio) according to the project manager’s judgment. Equation: EAC = AC + [(BAC – EV) / (CPI × SPI)]