Often, the progress of costs is used as the reference measurement for the project completion. This is indeed the most affordable method, but surely it cannot be a reference point, because the project may not have been completed when the funds ran out!
The only reliable system to determine the project status is calculating the physical progress which is also the basic key to evaluate reliable predictions and estimates to complete.
Contrary to planning, calculating the physical progress is a bottom-up process that needs to start from the evaluation of every single activity.
Once the status of each activity has been evaluated and registered, PDA calculates the physical progress status according to the defined Work Breakdown Structure and to the weight given to the different levels that the project startup divided the scope of work into.