Didn't know it had an official name, but almost all the systems we've used involved the backprojection of the EV to the planned schedule to get the schedule variance
Earned Schedule (ES) is not related to Planned Value (PV) and Schedule Variance (SV) in Earned Value Management. ES is in units of time and akin to Earned Value (EV).
Earned Schedule Management is described by the Project Management Institute as an emerging practice and to be used with caution.
It's genesis is in the fact that SV and Schedule Performance Index (SPI) don't reflect real schedule performance towards the end of a project.
- SV = EV – PV
- SPI = EV / PV
At completion:
- PV = Budget at Completion (BAC)
- EV = BAC
- SV = BAC – BAC = $0
- SPI = BAC / BAC = 1.00
So as a project nears completion SV will trend towards $0 and SPI will trend towards 1.00, even if a project is behind schedule.
Earned Schedule Management attempts to address this issue by comparing Planned Duration, Actual Duration and Earned Schedule, all in units of time, in the same way that Earned Value management compares Planned Value, Actual Cost and Earned Value, all in units of $.
Check out the website in my initial post for more information.
I did, and summarized the result from the website, which is that you use EV to backproject to the PV and the resultant abscissa value is the ES. The delta between AT and ES is the schedule variance.
As far as I'm concerned, it's a bunch of hyperbole to claim that someone using EV will get full schedule credit when the project is late. A late completion is late, period, regardless of what your EV is. No competent program manager looks only at the EV as a measure of project progress or success.
First thanks to dbuzz for bringing this subject up, and bigger one for the link to the earned schedule website.
I work with a construction project management company and we use EVM for project monitoring and control till the end of our projects.
While agreeing with IRstuff on one part, that a late completion is late regardless of the EV, I also believe that project managers and controllers should begin to see the enormous potentials in Earned Schedule analysis.
The idea is not only to see the end result of a project schedule performance but to aid in identifying schedule delays before they get out of hand
I think there's some sort of misconception about EVM not showing schedule variances.
A good EVM structure should have sufficient granularity that a single late task should be clearly evident. That, coupled with a decent critical path analysis will flag problems with 1 week of discovery.
You cannot use the total rollup on a $15 million program to find small problems. By the time they show up in earned schedule OR earned value at the summary line, it's already too late.
A typical, perhaps overboard, example is where Lockheed Martin, ran EV on all tasks, with no task larger than 80 manhours. While a bit excessive, no single problem would escape notice by more than 1 week.
It's a quirk that the SV and SPI measures in traditional EVM can be misleading, because as PV and EV approach BAC, SV trends towards $0 and SPI trends towards 1.0, regardless of actual schedule performance.
Would be really interested to hear if anyone out there has used Earned Schedule method.
