Basically i need to know how much work is completed or the progress through Gantt chart. The chart needs to show some kind of progress based on fields like duration of task or any other defined fields. If the duration of task is 30 days and the user has logged in for 15 days then the chart mush show at least 50% progress. Is there a way i can do it?

I am attaching a file as an example of how i need a gantt chart.

Please let me know. Thanks!