a teacher in first 2 hours in a single week day

[y]

I want to have a teacher working one day (no matter which one) only the first 2 hours, and all the other 4 days according to the general constraints. How can I do that? I tried with "... hourly interval max days per week" but this is not the right constraint.

Any ideas please?

[Liviu Lalescu]

1) If you don't care if he is free or working in the first 2 hours in that day, teacher interval max days per week is the solution. Interval = hours from 3 to end of day, max number of working days = n_days_per_week - 1;

2) If you want to make him work for sure in some slots, you can use the new constraint activities occupy max time slots from selection;

3) I am not sure if (1) and (2) can be combined for your case. I think not;

4) Maybe you could use teacher min days per week and min hours daily, if you have 5 days per week in your institution.

Please let me know further details.

[y]

In my school I have 5 days per week and 7 hours per day (namely 1,2,3,4,5,6,7). I want to use this constraint for 2 teachers. Both come 5 days per week (min days per week = 5) and they have min hours per day = 2.

1) If you don't care if he is free or working in the first 2 hours in that day, teacher interval max days per week is the solution. Interval = hours from 3 to end of day, max number of working days = n_days_per_week - 1;

I already tried that, but it did not work! I think I made a mistake though, since I put hours from 3 to 7, not to the end of the day. I found another thread in this forum, where you explained that if I put "to 7" this means that this teacher will not work the 7th hour. This made my timetable extremely difficult. I'm trying this again as you say...

2) If you want to make him work for sure in some slots, you can use the new constraint activities occupy max time slots from selection;

Is this a new constraint in the snapshot version? Because I use the stable one and I can't find it...

3) I am not sure if (1) and (2) can be combined for your case. I think not;

I'm not sure I understand how (2) works to reply to this.

4) Maybe you could use teacher min days per week and min hours daily, if you have 5 days per week in your institution.

I already use this. But I want to put these 2 teachers to work one day (out of 5) up to the 3rd hour (not the 3rd one though). I don't mind if they will work 1 or 2 hours this day, as long as they are free from the 3rd hour upwards.

Thanks for your reply. I'll post again with the results of trying (1)!

[Liviu Lalescu]

I already tried that, but it did not work! I think I made a mistake though, since I put hours from 3 to 7, not to the end of the day. I found another thread in this forum, where you explained that if I put "to 7" this means that this teacher will not work the 7th hour. This made my timetable extremely difficult. I'm trying this again as you say...

It was a mistake to say that "-to 7- means will not work in the 7th hour". Where is it, so I can correct it?

From 3 to end of day, max 4 times per week. Maybe you put less than 4?

[Liviu Lalescu]

Is this a new constraint in the snapshot version? Because I use the stable one and I can't find it...

Yes, it is one of the two new constraints.

[y]

I already tried that, but it did not work! I think I made a mistake though, since I put hours from 3 to 7, not to the end of the day. I found another thread in this forum, where you explained that if I put "to 7" this means that this teacher will not work the 7th hour. This made my timetable extremely difficult. I'm trying this again as you say...

It was a mistake to say that "-to 7- means will not work in the 7th hour". Where is it, so I can correct it?

From 3 to end of day, max 4 times per week. Maybe you put less than 4?

So, in my case "from 3 to end of day"="from 3 to 7"??
I'll search again to find the thread. Maybe I didn't understand correctly. I'm going to school now, so I'll be back with this in the afternoon.

No, I put 4 days, I'm sure about that...

[y]

Is this a new constraint in the snapshot version? Because I use the stable one and I can't find it...

Yes, it is one of the two new constraints.

I see. I downloaded, but since it is a bit urgent to get a final timetable, I'll stick to the stable one. Later on, I'll switch.

Thanks again, for the replies and all your efforts to provide such a great software! You can't imagine how complicated my timetable is, and FET always gives many timetables to choose from! It never fails!!!

[Liviu Lalescu]

So, in my case "from 3 to end of day"="from 3 to 7"??
I'll search again to find the thread. Maybe I didn't understand correctly. I'm going to school now, so I'll be back with this in the afternoon.

Say you have 4 hours per day: 8:00, 9:00, 10:00, 11:00. Then, to specify the first two hours, interval start = 8:00, interval end = 10:00. To specify the last two hours, interval start = 10:00, interval end = End of day.

You said that adding this constraint made the timetable very difficult. This should normally happen only if the teachers are very difficult.

[Liviu Lalescu]

I see. I downloaded, but since it is a bit urgent to get a final timetable, I'll stick to the stable one. Later on, I'll switch.

Actually, the current snapshot is ready for production, I am waiting a few more days for possible last minute adjustments and translations updates. I hope that the new version will be out on Friday 21 Oct. 2011 or Monday 24 Oct. 2011

Thanks again, for the replies and all your efforts to provide such a great software! You can't imagine how complicated my timetable is, and FET always gives many timetables to choose from! It never fails!!!

Thank you for appreciation! Maybe you would like to write about that in the feed-back section of the forum and/or guest book.

[Silver]

Since the small number of teachers so the easiest way to solve this problem are:
" A teacher's not available times"

[y]

Since the small number of teachers so the easiest way to solve this problem are:
" A teacher's not available times"

This doesn't work in my case, since I don't want to fix a particular day to have the 2 first hours. I want FET to decide which one is the more convenient, according to the other constraints.

[y]

Say you have 4 hours per day: 8:00, 9:00, 10:00, 11:00. Then, to specify the first two hours, interval start = 8:00, interval end = 10:00. To specify the last two hours, interval start = 10:00, interval end = End of day.

That is what I meant before, when saying that interval end specifies the end of the lessons, excluding the "end" hour. If I'm correct, I can understand why it didn't work in my case (5 days/week, 7 hours/day):

I put from 3rd hour to 7th hour, max days = 4. This actually means that this teacher for 4 days can teach from the 3rd up to 6th (including 6th) hour. This leaves out the 7th hour for all 5 days. This is the reason why FET could not produce a timetable. Am I correct?

Actually, the current snapshot is ready for production, I am waiting a few more days for possible last minute adjustments and translations updates. I hope that the new version will be out on Friday 21 Oct. 2011 or Monday 24 Oct. 2011

I think I'll wait for the official one then

Thank you for appreciation! Maybe you would like to write about that in the feed-back section of the forum and/or guest book.

What feedback would it be useful to you? Do you want the whole program, constraints or anything else? Please feel free to ask, this is the least I can do. I'll find the guest book as well

[Liviu Lalescu]

Say you have 4 hours per day: 8:00, 9:00, 10:00, 11:00. Then, to specify the first two hours, interval start = 8:00, interval end = 10:00. To specify the last two hours, interval start = 10:00, interval end = End of day.

That is what I meant before, when saying that interval end specifies the end of the lessons, excluding the "end" hour. If I'm correct, I can understand why it didn't work in my case (5 days/week, 7 hours/day):

I put from 3rd hour to 7th hour, max days = 4. This actually means that this teacher for 4 days can teach from the 3rd up to 6th (including 6th) hour. This leaves out the 7th hour for all 5 days. This is the reason why FET could not produce a timetable. Am I correct?

Actually, your mistake means: FET will produce a timetable easier, but you may end up with a wrong timetable (hour 7 used 5 times).

Actually, the current snapshot is ready for production, I am waiting a few more days for possible last minute adjustments and translations updates. I hope that the new version will be out on Friday 21 Oct. 2011 or Monday 24 Oct. 2011

I think I'll wait for the official one then

Thank you for appreciation! Maybe you would like to write about that in the feed-back section of the forum and/or guest book.

What feedback would it be useful to you? Do you want the whole program, constraints or anything else? Please feel free to ask, this is the least I can do. I'll find the guest book as well

Thank you for the guest book entry! Any thoughts you may have, share with us.

[y]

Actually, your mistake means: FET will produce a timetable easier, but you may end up with a wrong timetable (hour 7 used 5 times).

This was not the case though, since I have already max gaps/day=1 constraint! This combination made the timetable really difficult to solve, i.e. I had to stop it after 1 hour. Now, I tell FET to produce 10 timetables with limit=15min, and generally I get 9 out of 10! Great

Thank you for the guest book entry! Any thoughts you may have, share with us.

Fine...

[Liviu Lalescu]

Actually, your mistake means: FET will produce a timetable easier, but you may end up with a wrong timetable (hour 7 used 5 times).

This was not the case though, since I have already max gaps/day=1 constraint! This combination made the timetable really difficult to solve, i.e. I had to stop it after 1 hour. Now, I tell FET to produce 10 timetables with limit=15min, and generally I get 9 out of 10! Great

Hmm, this is no good.

1) I think you made other mistakes and FET is good in this aspect.

2) If you didn't make other mistakes, FET has a problem here.

3) It was just bad luck.

So, please:

a) Send me your file (by email).

or

b) Try on your new file to make the constraint from 3 to 7 (wrong). It should solve as fast as now.