earned value and physical percent complete

Question

I am a relatively new scheduler to my company and new to project scheduling and earned value. My company has training sessions but some things remain unclear and the answers I am getting from some folks here do not make a lot of sense.

I am told there are several ways of claiming % complete and that each way has issues with them in terms of subjectivity or accuracy. I was told that physical % complete is the most accurate since it's something you can count. However, it does not make sense in terms of how planned value (PV or BCWS) is calculated and how I would take EV.

Here is the issue: I have three team members working a project that is supposed to last 20 days. 20 is my duration. This project will cost (BAC) $6,400. So my cumulative budget (S curve) across those 20 days is pretty much a straight line going up. So PV at day 10 will be $3,200.

Physically, the work is what they call back loaded so by day 10, they will only be 30% physically complete, so EV will only equal $1,920. This would mean that we are behind schedule when we really are not behind. Also, assuming costs are what they are supposed to be, AC would be, $3,200 and then this would mean we are also overrunning costs which would also not be accurate.

I am confused as to how physical complete is desired but then this scenario would make everything not accurate.

Help!!!

Answer 1

I would map your physical % complete with the PV/BAC for any given period, and then when you complete a specific physical % of the work, you can claim the mapped PV/BAC as your earnings.

This is a graph that shows the S-curves for PV/BAC, the top line; % work, the second top line; % complete, the third line; and physical %, the bottom line. The physical % lags as was your example.

So let's say we are in period 4 and you completed the work on time, you would be about 45% physical complete, which maps to 86% PV/BAC complete (draw a vertical line from the bottom curve all the way to the top line curve and then a horizontal line to the y axis.) Therefore, for 45% physical complete, you would claim 86% EV or BCWP.