Productive time and Non-productive time measure based on activity. On the other hand, activity measures are based on keyboard clicking and mouse clicking.
Suppose your employee is working with 90% activity for 10 hours. In that case, 9 hours will count as a productive time, and 1 hour will count as a non-productive time cause the activity is 10% less.

If your employee's activity 100% for 10 hours. In that case, 10 hours counts as a productive time.