How does Primavera P6 calculate Planned Value Cost for Activities without linear distribution (using Resource Curves or Manual plan) in Earned Value Management
When we use Earned Value Management technique, we focus on:
- Planned Value Cost (PV) = Budget At Completion * Schedule % Complete
- Earned Value Cost (EV) = Budget At Completion * Performance % Complete (usually equal to Activity % Complete)
- Schedule Variance (SV) = EV - PV
- SV > 0 : project is good, ahead of schedule
So Planned Value Cost play a very important role here.
By default when we assign resource to activity, the unit is distributed equally (linear). Then calculation of Planned Value is as above.
However in reality, we always adjust unit for each month/week differently.
Then How 'Planned Value' is calculated for Activities without linear distribution, by using Resource Curves or Manual distribution?
I will explain it in this article.
We have an simple project:
The resource assignment use Back Loaded curve:
The resource curves are divided into 5% sections. Each section has a 'Curve %' value, so that you can specify how much actual work is to be performed in each '5%' increment of the linear duration.
Shown below is an example of the default 'Back Loaded' curve. As you can see, between 0 and 5% of the activity duration, only 3.5% of the work is scheduled to be performed, but between 50 and 55% of the duration, 6.5% of the work is scheduled to be performed.
The activity is 10 day duration. Now let say we are at 5th day.
The calculation for "Schedule % Complete with Curve" is total all of the interval work % values.
Schedule % Complete with Curve = 3.5 + 3.5 + ... + 3.5 = 35 %
PV = Schedule % Complete with Curve * BAC = 35 % * 100 = 35 $
However we can see the "Schedule % Complete" show 50%. Because it is not the "Schedule % Complete with Curve". It is the default "Schedule % Complete" of P6 which always show linear distribution.
If we want to show "Schedule % Complete with Curve". We can use the User Defined Field feature.
1. Create an "Activities" User Defined Field (UDF) called "Schedule % Complete with Curve" with a Data Type of Number.
2. Add this UDF as a column in the activities list.
3. Create an "Activities" Global Change as follows:
Then Schedule Curve % Complete = Planned Value Cost / Budget At Completion
And Schedule Curve % Complete = Schedule Curve % Complete * 100
4. Run Global Change and we can see the updated Schedule % Complete with Curve
If we have multiple activities in WBS, and want to see the summary “Schedule % Complete with curve”, you can look at the default Schedule % Complete. Its calculation is Summary PV / Summary BAC. So it will show the right %.
For Activities having Both 'Curve' And 'Non-Curve' Resources
If an Activity features multiple resource assignments, some of which use Resources Curves, and some of which do not, then the Planned Value will be calculated correctly for each resource assignment, using the appropriate method, and then summed at the activity level.
About the Author : Khuong Do
Khuong Do is a Project Planner / Scheduler in Civil Engineering, Transportation, and Oil & Gas Industry. He has worked as a Primavera Consultant Specialist since 2006 and willing to share his passion for Primavera through lots of Tips & Trick on his personal blog : https://doduykhuong.com
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