Author Topic: Time table not generating  (Read 1274 times)

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harvestglobal.com

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Time table not generating
« on: May 29, 2015, 01:13:13 PM »
PFA fet file, time table is not generating, please help.

Volker Dirr

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Re: Time table not generating
« Reply #1 on: May 29, 2015, 04:36:26 PM »
There is a problem with activity No: 196, Id: 278, Teachers: Shaistha, Subject: IS/VE, Activity tags: , Students: Rec D
it can't be placed. looks like the are not enough time slots left.

please generate a timetable and stop after some time. then view the incomplete result and try to place that activity manual. i guess/hope you will see the problem yourself fast.
« Last Edit: May 29, 2015, 04:52:32 PM by Volker Dirr »

Volker Dirr

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Re: Time table not generating
« Reply #2 on: May 29, 2015, 04:58:13 PM »
it look like there are to many teachers only allowed to work in the afternoon. as soon as i allow one teacher to work also in the morning, then it is possible. (for example if Halima is allowed to work in the morning.) So: please rethink about not available times. if you can't change that: please rethink about the activities of that teacher. please give them other activities.

harvestglobal.com

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Re: Time table not generating
« Reply #3 on: May 29, 2015, 10:06:35 PM »
Thanks for the reply.

Yes it is correct, those set of teachers are available only for the defined period of time
Ex: Halima is there for 20 periods out of which 5 periods are break periods, but the work load for her given is only 10, she is still free for 5 more periods, so this should be possible.
The same is with the other teachers.
Please help. Thanks

harvestglobal.com

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Re: Time table not generating
« Reply #4 on: May 30, 2015, 12:32:42 AM »
Any solution?

Volker Dirr

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Re: Time table not generating
« Reply #5 on: May 30, 2015, 01:18:21 AM »
You forgot to think about the students!

Easy example:
A school has 6 hours per day with 5 days. So overall 30 hours per week.
2 Teachers has workload 18. So you maybe give them 24 free time slots.
So it should be possible.
But you are wrong if you forgot the students!
If both teachers teach 15 hours the same students and you allow both teachers only wo work at Monday, Thuesday, Wendsday and Friday; then it is impossible to solve the timetable, because nobody can teach on Friday.

You do the same bug with morning and afternoon!

One solution is for example this:
Select teacher Halima and allow only timeslots 10.55 - 12.55. That are only 15 time slots. (Currently you allow 20 timeslots). But even this sound more difficult; that table solve in 2 seconds.

It doesn't need to be exactly that teacher. You can do similar tricks also with an other teacher (or with mixing that trick with several teachers. I didn't tried, maybe it is even enough to do that trick just a single day.)
« Last Edit: May 30, 2015, 02:09:48 AM by Volker Dirr »

Volker Dirr

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Re: Time table not generating
« Reply #6 on: May 30, 2015, 01:32:38 AM »
Or you can for example allow Halima only from 11:35-12-55. That are only 10 time slots. Even it sound more difficult. That timetable solve in around 10 seconds. Like i said: you can do that also with other teachers. You can also mix that solution. So maybe do it only at one day with other free slots.
« Last Edit: May 30, 2015, 01:34:43 AM by Volker Dirr »

harvestglobal.com

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Re: Time table not generating
« Reply #7 on: May 30, 2015, 02:32:56 AM »
But if you see there are 5 days and 8 periods per day, so with this it should be possible right?

Class teacher work load is max 45 periods per week, for part time teachers it is 10 periods per week.

Volker Dirr

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Re: Time table not generating
« Reply #8 on: May 30, 2015, 02:49:15 AM »
You are talking about my example or your file?
If you talk about my example: No, even with 8 hours per day it might be impossible, (for example if you set min 2 hour per day for students)
You always need to think also about students and rooms.

If you talk about your about you file. Please read my post one more time. You forgot to think about morning and afternoon lessons of the students. Your file is impossible that way. You must allow at least one more teacher to work a few hours in the morning. As you can see, even i set a "more difficult" constraint for teacher Halima (I REDUCED the number of allowed time slots), the timetable change from "impossible" to "very easy". You can do the "trick" of course also with other teachers and/or other morning hours if you want. But you can't say that all that so many teachers are  allowed to work in the afternoon only, because there are not so many students in the afternoon available, sometimes the students need also hours in the morning.
« Last Edit: May 30, 2015, 03:14:13 AM by Volker Dirr »

harvestglobal.com

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Re: Time table not generating
« Reply #9 on: May 30, 2015, 05:50:03 AM »
Thanks will look into it again