# How can an EV be calculated when there are different versions of a project plan?

There is a project manager who is trying to come up with a way to calculate EV under a specific situation where there is a project management system which allows different versions of project plans.

The 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 revising the project structure (adding/removing tasks) and project costs. During the running of the project, various cost are also charged to the project.

Here is an example of the project:

``````Revision 0 (cost/schedule plan):

month  |  1  |  2

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

Revision 2 (revised at end of month 2)
month  |  1  |  2
task 1 | 200 | 300
task 2 | 200 | 100
``````

Actual Project Cost:

``````month  |  1  |  2
``````

In this case, how can the PM modify the formula (shown below) to calculate the EV in this situation? Is there a better formula to use in this situation?

Here is the formula the PM is working with:

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