Planned % vs Actual%

In addition, I would suggest closing out/storing the period performance data (Tools/Store Period Performance) after you’re done evaluating the current schedule prior the next update. This is so because P3 tend to evenly distribute earned value to the entire duration of an activity even if the periodic % progress differ from one period to the next.

That way, previous or periodic performance is "preserved", especially for activities that will take several updates before reaching 100%. It is a good measure when generating report whereby current performance is gauged not only against the baseline but to previous periods updates as well (i.e. compare this month versus last month’s performance.)

Rey