Limit a teacher to one of the 2 pair days

[russell]

First of all thanks for this great software.

I have a teacher come to school in Monday and Wednesday OR in Tuesday and Friday. How to implement this constraint in FET? (I have some other constraint related to that teacher and his activities)

[Liviu Lalescu]

It would be easy to make a change in the code for this. But I don't know how to make it a general constraint with FET-style-name.

These tricks might work:

- Teacher not available on Thursday;

- Max days per week for this teacher = 4;

- Add two dummy activities for this teacher, duration = number of hours per day. Not allowed on Thursday (not really needed, because the teacher is not available). Then min+max 3 days between them;

I hope I got all the details. Please correct me if I am wrong.

[russell]

Thanks for your reply.

Can you please explain to me about "min+max 3"?  Dose it mean exactly 3 days distance (Tuesday to Friday)?

Dose your solution work for days with different hours (Monday has 8 hours and others 6)?

[Liviu Lalescu]

Can you please explain to me about "min+max 3"?  Dose it mean exactly 3 days distance (Tuesday to Friday)?

The constraint min, then max days between activities.

Dose your solution work for days with different hours (Monday has 8 hours and others 6)?

If the teacher cannot have more than 6 working hours on Monday, use a constraint activities occupy max time slots from selection for his activities, so he has no more than 6 working hours on Monday (less work for you).

If he can have 7 or 8 real working hours on Monday, a lot of work for you: constrain each pair dummy - real activity pair for this teacher to not be on the same day (min 1 days between activities).

Please think of other solutions, if you want.

[russell]

Most of the "select a day's group from a set of the day's group for a teacher" constraints can implement by other FET constraints. But if FET has a specific constraint for that it would be better. Thanks

[Liviu Lalescu]

Maybe better "Teacher works in a days group from a set of days groups".

Do you use official FET or the custom FET mapr (multiple activities per room) for US high-schools?

I might consider to add this for the official FET, for custom FET mapr (derived from FET mapr) or for a custom version derived from zero from the official, but as my time permits.

Anyway, I added this in the TODO. Thank you for the suggestion!

[russell]

I just want to edit my post but yours is more appropriate.

Thank to you I done my timetabling (I used FET mapr). So just keep it in your mind for future releases of FET.

[Liviu Lalescu]

I am glad it was useful. It is very interesting that FET mapr was used by other people than it was designed for.

I modified my post above.