Earned Value calculation

[George2u]

Hi All,

I am trying to come up with a way to calculate EV under a specific situation where we have a project management system which allows different version of project plan, the way it works is described below:

PMs starts with a initial project plan, cost are allocated to different tasks across different period, at the end of each month, PMs review their project plan and revise the plan according, this includes revise the project structure (adding/removing tasks) and project costs, during the project running, various cost are also charged to the project.

here is an example of the project:

Revision 0 (cost/schedule plan):

month 1 month 2
task-1 100 200
task-2 200 100

Revision 1 (revised at the end of month 1)
task 1 200 200
task 2 200 100

Revision 2 (revised at end of month 2)

task 1 200 300
task 2 200 100


actual cost

month 1 month 2
task-1 200 300
task-2 200 100

In this case, how can I come up with the calculation for EV?

I am trying to calculate PV/EV/AC for creating diagram.

I was thinking about the following formula:

PV= PV of previous plan
EV= (actual cost Todate)/(total cost of new plan) * (PV according to previous plan)
AC = actual cost todate.

however I am not sure whether the above formula can actually reflect the status of project plan, if anyone can provide some insight, it will be much appreciated.

 

[George2u]

the above formula can also be expressed as below:

PV= PV of previous plan
EV= (AC)/(BAC of current new plan) * (PV according to previous plan)
AC = actual cost todate.

 

[George2u]

sorry should be:
EV= (AC)/(BAC of current plan) * (BAC of previous plan)

 

[jmort253]

Hi George2u,

There are some concerns about the methods for which you're using to calculate your EV. From what I've read here on this post about calculating EV, your baseline really wasn't intended to be modified in this manner.

In summary, if you were to take this approach, you would need to keep each baseline completely separate from the others so that you aren't mixing the data. Each variable would have to be captured differently for each baseline so that each baseline has it's own EV, PV, and AC data.

Hope this helps,
James

 

[George2u]

Thanks, James.

I figured out that the only way to do it properly is to use the original revision as the baseline.
i.e. BAC and PV will come from the original revision.