Manage the students that failed some courses

[Peter Johnson]

Hi, I faced a problem that I do not know how to handle it in FET.

Suppose many students, who started their semester in October 2018, failed many of their courses. Let's call these students S1, and assume half of them passed all the courses (Let's call these students S1-P), but the other half failed half of the courses (Let's call these students S1-F). A new student set will start their education in March 2019 (let's call them S2), and we want to generate a timetable of all university for March 2019.

S1 and S2 should take some courses separately according to their chart. For this part, we can create the activities and select the corresponding student for each, so far so good. The problem is the situation that S1-F should be able to take some of the courses of S1-P as well as S2, but the priority is with S1-P and S2 for scheduling. For example, we want to put a "Max Days per week" constraint for S1-P and S2. Also, we need a timetable for S1-F as dense as possible (to make sure they will not come to university many days).
As a short story, we want to generate a timetable for S1-P and S2 according to their constraints, after that, find a good time for activities of S1-F.

How can I do that?

[Volker Dirr]

Let's assume student s1,s2 and s3 has got 30 hours per week.
Maybe s1 done all courses fine.
Maybe s2 fails the first half of all his courses, then he need to repeat 15 hours.
Maybe s3 fails the second half of all his courses, then he also need to repeat 15 hours; but the other 15 hours.

So if s1, s2 and s3 will get into the next year, they will again have got new 30 hours.
since s2 failed 15 hours, his timetable need 30+15=45 hours.
since s3 failed the other 15 hours, these 15 hours can't be at the same time. So he also only need 30+15=45 hours, but in fact the whole timetable need 30+15+15=60 hours, since the hours can't be at the same time.
I hope you will see the problem. If you have several guys that failed only a single course. You need at the end double as many space in the timetable.
If you know repeat this with the next year, the needed slots will increase very fast.
I fear it will be impossible in most cases.

[Peter Johnson]

Thanks for your reply. Actually, in the mentioned example, some courses of S1-F can be presented at the same time with the courses of S1-P and S2. But the point is that we do not want to change the S1-P and S2 schedule because of S1-F. We want to find a timetable for S1-P and S2 and then manage the timetable of S1-F in the best possible way according to the S1-P and S2 schedule. At the moment, when we run the program S1-F may affect S1-P, S2 timetable, which is not what we want.

[Volker Dirr]

Even if some courses can be at the same time. It will be impossible if many students failed. Difficult to say what "many" is. Many might be already a very low number of students (less then 10!); depending on your data set.