As we discussed in my last post Technique for Computing Performance Percent Complete , WBS Milestones can be used to calculate Performance Percent complete and Earned Value. They can be used in cases where you have fixed weighted milestones for a WBS and you want to calculate your Earned Value against them. If you prefer to choose this option then Performance Percent Complete is distributed equally amongst the activities under the WBS.

To assign WBS weighted milestones for a particular WBS you will need to do the following:

1. Choose Project, WBS.
2. Select the WBS value that you want to assign weighted milestones to and then click the Earned Value tab.
3. Under Technique for computing performance percent complete, click the WBS Milestones percent complete option

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We will see how choosing WBS Milestones affects the calculations in Primavera.

1) We have 2 activities A1,A2 with resources assigned and cost data as shown in the picture below :

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2) We update the project and check the Earned Value calculations by toggling between Activity % Complete and WBS Milestones and see the difference

Case 1 – Technique for computing performance Percent Complete – Activity % Complete

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If we choose Activity % Complete to calculate Performance % Complete then our Earned Value for both the activities is calculated as: EV = Perf% X BAC

A1 – EV=50% X 80,000 = 40,000

A2 – EV =50% X 40,000 = 20,000

Case 2 Technique for computing Performance Percent Complete – WBS Milestones

In this case we create WBS Milestones for our project with their weightages. We then update these milestones as and when they get completed. The cumulative Percent Complete for the milestones is calculated as 33.33%.

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This cumulative percent is distributed amongst the activities under that WBS and our Performance Percent Complete for A1 & A2 becomes 33.33% in this case. The EV for A1 & A2 becomes 26,666 & 13,333 respectively.

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WBS Milestones is one of the alternate means to calculate Performance Percent Complete in our project. Choosing WBS milestones is an option when EV depends on completion of certain important milestones for a WBS, rather than all the activities under it. It is important to choose the right option for computing Performance Percent Complete as it directly affects our EV.