ProjeQtOr implements "Work driven" project management.
But What is it ?

The main principle is :

• customer requests a change (or else) : in most cases he requests for a target date (called requested end date)
• Project Leader, depending on resource avaialbilty, assigns resources : this defines assigned work
  and runs planning calculation to determine possible target date
  with possible ajustments and new calculation to find best planning
• with complete planning, Project Leader can commit on target : validated work, validated end date
• when working, resources enter real work, day by day : real work,
  and update left work depending on what is left to do (left work is automatically updated when real work is entered, but it must be re-estimated)
• planned work is automatically calculated as real work + left work

So

• validated work = committed work
• assigned work = validated work dispatched to the resources
• real work = work really done by each resources
• left work = new estimate of left work
• planned work = new estimate of full work = real work + left work

And from this data :

• real progress = real work / (real work + left work) = real work / planned work
• expected progress = real work / validated work (where progress should be if validated work was correct)

So, to get the correct progress, the left work must be updated :

• by resource on real work allocation
• by Project Leader on assignment in the activity

So now, why only "work driven" principle, why not let the resource estimate the progress ?
Because of expertise and long practice of project management.
Just try this once or twice, you'll be surprised ...

• consider a 10 days task
• after resource has worked 5 days, meet him and ask : "what is your progress on the task ?"
• 99% of change you get : "50% !"
• then, slightly change the question and ask : "how much work do you need to finish the task ?"
• you could be surprised to hear : "7 days !"
• so you request some explanation : "but you just said you did half of the work ?"
• and don't be surprise to hear : "Yes !!! I did half of what's to be done" (half of the rules, of half of the specification), "but I left the hardest for the end, so the end will be a bit longer" ... or alternatively "but I did not run unit tests yet, and I will manage all at the end" ... or possibly "but when all is done I'll have a little of tuning to integrate components and have them work together"...

I heard these so many times that I really made my mind : only plan from "work" and fight to have "left work" restimated at least on a weekly basis.

This was my 2 cents on project Management, hope it can help...