Roughly you could have two kind of problems:
- You don't know how logically solve the problem, that is you're not able to formulate the right algorithm.
- You have no programming skills to actuially implement the algorithm.
One approach for dealing with the problem could be collecting statistical data (if available) on relative speeds of employees in completing assigned tasks (I know this would depend on many different factors) and the using this information to predict the progress of the activities. The actual progress of such activities could be a feedback to your predictive algorithm,
Point 2 is, in my opinion, simpler: you have just to study and do some experience with you favourite programming language (you know: what is a software developer without programming skills?).