how to do Allocation of Invigilators for unified exams ?!

[hisham54321]

Hello All,
I'm a new user of  the amazing program FET and i have the following question:

how I can allocate the 49 exam sessions equally for 12  Teachers /Invigilators?  without any space (relax time ) for each teacher without conflict in his/her time?

the details are shown in the attached image ...

because I want to know how FET can solve like these problems or any other  scenarios from this category
if the numbers of sessions /teachers/rooms  increased or decreased   without any conflict between the teachers time

[Liviu Lalescu]

Hello, hisham54321!

Please tell me:

1) Without space (relax time), means without gaps for teachers?

2) Each slot of the 49 should have a single teacher?

3) Each teacher should have minimum 2 activities and maximum 5?

4) Could you show us an example timetable?

5) Could we assume we know the exact number of activities of each teacher? (I think not.)

[hisham54321]

Hello  Liviu Lalescu,
my responses are on red
1) Without space (relax time), means without gaps for teachers?
yes, that's what I mean
or at least as minimum  gaps as we can

2) Each slot of the 49 should have a single teacher?
I mean for each exam session there should be only 1 teacher

3) Each teacher should have minimum 2 activities and maximum 5?
there are 49 exam sessions and 12 teachers which mean I need about  49/12 = 4.083  session per teacher
you are right because we don't have a better choice let it be  minimum 2 activities and maximum 5

4) Could you show us an example timetable?
well, I don't have one ready now because this is an example of a problem we are facing most of the time and many friends tell me that FET will find a solution for it.
and Because Fet has a lot of setting I don't know where to go  for this reason I asked my question here


5) Could we assume we know the exact number of activities of each teacher? (I think not.)
some times we need to set this parameter for some  teachers and sometimes we don't need


Finally ,  thanks a lot for your help

[Liviu Lalescu]

Actually I did something yesterday. See the attached input file and result HTML. I added one teacher with 5 hours and the rest with 4 hours.

The only problem is that it has 3 teachers with 1 gap (there are 3 disabled constraints max days between activities) - T10, T11, and T12. But you said this is not a hard constraint.

There might be better solutions if we allow less or more hours for teachers (not so well distributed, but chosen by FET). But it would mean a more difficult approach, maybe customizing FET for you, which is I think more difficult for your case.

PS: Don't worry that FET will report an old version. Ignore the warning, it is the future FET version on my hard disk.

[Volker Dirr]

hmm... Maybe i missed it, but why did you (Liviu) allow only 1 activity per day for a teacher? He didn't wrote such a rule and I think can do much more exams per day.

[hisham54321]

Hello Liviu,
I like the result, it is very interesting but can we add a rule to reduce the number of teachers traveling between rooms because if we keep the teacher in the same room it will be better for them.

Regards
Hisham

[Liviu Lalescu]

Hello Liviu,
I like the result, it is very interesting but can we add a rule to reduce the number of teachers traveling between rooms because if we keep the teacher in the same room it will be better for them.

Regards
Hisham

Hello, Hisham,

I obtained after some work the attached timetable. If you open the data_and_timetable.fet you will obtain the same timetable. Otherwise you can open the liviu28.fet. You can generate multiple and choose the best.

I hope you will like it. Please let me know.

There are possible many other variants, if you adjust the constraints. Or customizations are possible, to express the exact room changes constraints. This involves more work.

I ordered the activities for each teacher (the constraints two activities ordered).

[Liviu Lalescu]

hmm... Maybe i missed it, but why did you (Liviu) allow only 1 activity per day for a teacher? He didn't wrote such a rule and I think can do much more exams per day.

No Volker, FET days are real-life hours and FET hours are real-life rooms.

[Volker Dirr]

ah. ok. I read too quick.

[Liviu Lalescu]

I worked some more, and now seems perfect. I derived you a custom version, see: https://lalescu.ro/liviu/fet/download/custom/hisham/

You have in this custom version an example (in the "examples" directory). See the time and space constraints. I added min gaps between room changes as 1 (you can remove if you don't care), and it is impossible practically (I checked) that a teacher from T10, T11, or T12 to have in the same room all activities if max room changes for every other teacher is 1 (maybe I did a mistake - you can double-check).

The room changes per day and min gaps between room changes assume real-life days (FET hours).

Please let me know.

I attach a solution (solves very easily). You can generate many more.

[hisham54321]

It is incredible results, and now I need to review your solution and to check it with other scenarios

Thanks, Liviu, I appreciate your effort from all my heart.

FET is very excellent and smart software, but it needs more tutorials or videos for beginners like me to understand it is capabilities.

[Liviu Lalescu]

I am glad it works for you! You are welcome. 

[Nagendra]

Liviu, I think you can increase the capability of official FET by giving an option to enable random assignment of teachers to rooms. Like you assign an activity (subject+student set) to a room if teacher(s) is/are also assigned to the room, then FET official can be used for regular as well as Exam timetables.

I don't think it is much difficult for you. It is just a suggestion to improve FET. I guess many users will be benefited.

[Liviu Lalescu]

I am not sure I understand correctly.

You can add activities only with teachers and assign them to rooms.

The "FET-mapr" custom version allows More Activities Per Room. But I don't like this custom version, is inefficient.

Some options cannot be added in the official FET, that is why sometimes a customization is needed.

[Nagendra]

I am not talking about 'More activities per room'. I am talking about assigning teachers automatically.

1) Say, activities are created with students and subjects (without teachers)

Currently, FET assigns these activities to rooms (subjected to the constraints).

Similarly, you can include an option to assign teachers automatically, if a user wants FET to do so. User may be given option to toggle/untoggle the feature of assigning teachers automatically.

This way official FET can be used for both Regular aswellas exam timetables