Is anyone knows how to use P6 to measure the progress based on the units/Resources?

I am using units and resources in my project but the calculation is not accurate when it comes to the activities which has more than one resources assigned. Performance % Complete and Labour Units % Complete are not equal.

If you want Performance % Complete to equal Labor Unit % Complete, The % Complete Type has be "Units". Percent Complete Type is under the "General" tab in activity details.