It is quite common that students need to pass all assignments in order to pass a course. So if for example a student has 2 assignments and a final exam, and fails one of these, he does not pass the course. Let's say a student gets 7 for assignment 1, 4 for assignment 2, and then a final exam with 8. Given that they all weigh 33% this studend would get a final grade of 6,3, but since he failed assignment 2, he has not passed the course.
It would be great to be able to add some requirements in the gradebook that would either override the final grade, or at least "flag" students that do not meet a defined requirement in defined assignments.