How does Project know which tasks are slipping?
When you tell it, by entering Actual Start and Actual Finish dates, or
by entering the Work on the appropriate dates. If the task has
slipped, the appropriate dates will be later than the planned dates.
Of course, you need to Baseline the project to be able to track all
this. I recommend looking up "Tracking" in the help files, and
searching this NG for the same. You'll find a lot of good information
on tracking. It is a multi-step process, but not very difficult.
I'd also strongly recommend NOT using %Complete as your primary
tracking input, for reasons that would take too much time to explain
here. You might search this NG for that also.
Hope this helps in your world.
