How long will it take to finish?

The topic of duration estimation is relatively new and few books cover it. But, since the authors actually wrote the foundational papers that derive the formulas for duration estimation, we understand it and can explain it for you.

As you can see above, the formula for duration estimation is quite simple. We just need to calculate the Earned Duration.

Here is an example of how to use calculate the Earned Duration:

Once we’ve found the Earned Schedule, we can estimate the final duration:

…. and show that it gives the right answer.

The Cost Estimate at Completion and the Duration Estimate at Completion both give the correct answer early in the project.