Generation Delay

[anisanjum]

hi,
I have more than 1100 activities.
It's not generating the TT.
Any ideas to shorten the delay will be appriciated.
Thanks.

[Volker Dirr]

help the algorithm if you know constraints that must be. I am talking about constraints that must not be added, because if you schedule, then these "constraints" will be respected automaticly, because they are forced by your dataset.

1. if you know a constraint must will be at a specific time, then use constraint activity prefreed time.
2. if you know that activities must be simultaneously, then also tell that by a constraint. (But be carefull, it will speed up only if these constraints compelling. most guys to misstakes here and generating (might be)/will be much slower.
3. also using activity constraint "a set of constraints occupy max timeslots" to the courses can improve speed pretty much.

[anisanjum]

Hi,
Now I have approx. 1600 activities.
When I add the Third constraint mentioned by you(ie an activity has a preferred time slots) then it's not generating the TT at all.
If removed the generates the TT with a little Delay.

This constraint when given to the FET,sometimes TT is generated and sometimes TT is not generated.

for ex-If I have 5 working days,
             I have 6 periods of science subject and I want them to be in the first hour of every 5 working days.
             Means FET will select any 5 periods of science and put in the First Hour.
             And I add this contraint.
             Then TT is not generated.
But,
            If I have 5 working days,
             I have 10 or 12 or 15 periods of science subject and I want them to be in the first hour of every 5 working days.
             Means FET will select any 5 periods of science and put in the First Hour.
             And I add this contraint.
             Then TT is generated.

Any kind of support will be appreciated.
Thanks.

[Volker Dirr]

nobody can answer that question without your dataset.
i bet it is impossible: for example because the science activities are always instructed by the same teacher and he isn't available always.

[anisanjum]

PFA fet file for time table
The constraint is all the class teachers should be in their respective classes for the 1st period for the entire week.

This constraint is applied to almost all the classes except a few. Please find below details which are not happening
Class 7A, Class teacher: Rekha Kumar, activity-Social Studies no of periods/week , No of working days: 5.
Class 7B, Class teacher: Amlorepava Mary, activity-Maths no of periods/week 7 , No of working days: 5.
Class 8A, Class teacher: Bhavani P, activity-English no of periods/week 7 , No of working days: 5.
Class 9B, Class teacher: Mahesh TD, activity-Kannada no of periods/week 6 , No of working days: 5.
Class 11A, Class teacher: Mangala Mary, activity-Kannada no of periods/week 8 , No of working days: 6.
Class 12A, Class teacher: Rajshekar V, activity-Physics no of periods/week 8 , No of working days: 6.
Class 12B, Class teacher: Muthu Kumar K, activity-Political Science no of periods/week 8 , No of working days: 6.

Note: If the teacher is handling more than one subject for the class the constraint is applied, where as if it is only one subject it is not applied.

I have reduced the file size couz I was not able to upload it.
Thanks.

[Volker Dirr]

You can compress files before uploading them if they are to big. Normaly simply do a right click on the file and compress (zip, ..).

FET complain about a lot of bugs if you try to start generating. You must fix that bugs first. (so in most cases you only need to delete them; but i don't know 100%, because it is your dataset and not my one.)
Please resent a fixed version.
Also add the problematic constraint (maybe it is already) which fails and tell me the exact constraint. (So it should fail with that constraint, but it shouldn't fail without that constraint.)
I will search your bug as soon as you done that that preliminaries.

[anisanjum]

Here,
chi.zip is without constraint works fine.
copy(2) of chi.zip has the constraints which doesn't let me generate the TT.
the constraint is
"A set of activities occupies max time slots from selection".
for the classes I mentioned earlier ie 7A,7B,8A,9B,11A,12A,12B.
Thanks.

[Volker Dirr]

ah. ok. that is impossible.
looks like you missunderstood that constraint.

i am not 100% sure what your intension is/was:

did you try to use my speedup trick (see my first answer)? (i must read your dataset much more detailed if i want to answer this)

or

did you try to give a teacher at least 2 hours in the first period?
in that case it is better if you select 2 activities per teacher and/by use:
an activity has a preffered starting time
or
a set of activities have preffered staring times
or
a set of subactivities have preffered starting times.

[anisanjum]

I tried Everything but it's the same.
Thanks.

[Volker Dirr]

the file you sent me is impossible, because i guess to didn't saw that it is "MAX", i guess you think it is "MIN", but it isn't.

i didn't tried yet, but i think the other should work if there is no other blocking constraint.

please try one of the constraints i wrote (with only 2 activities!).
also add only 1 teacher and try to generate. if it succeed try the next one. and so on. you will understand (hopefully) the problem much better if you add constraints step by step.

[Volker Dirr]

Oh... Sorry, i didn't read carefully enough.
i reduced the problem down to some activities of teacher Kumar.
Please check the attached very small file. it is your impossible dataset, i just deleted a lot of teachers, activities, ... and it is still impossible.

as soon as you delete (some) activities or constraints it solves again. Also for example if you delete the min n day constraints. (But also if you remove lunch or breakfast)

so please rethink about your activities and min n day constraints.
i saw you have many activities which are split into more parts then a week has days. don't forget that you checked the "consecutive if same day" option, which can stick only 2 activities together.

i think it will be much better if you split your activities into less subactivities and increase the duration.

I hope you understand the problem. I will think myself again tomorrow but i need to sleep now.

[anisanjum]

Okk..
Good Night.
But I have tried every possibility of mine but I am not able to solve.
Please give an answer which will make it generate the TT.
Also I have taken care of that "consecutive" stuff.
Because if I have 5 working days/week then I give max 10 subjects/week.
If it's 11 subjects/week,then I do it manually by giving any of the working day as 3 periods and rest as 2.
Please give some help if possible.
Thanks.

[Liviu Lalescu]

Looking at Volker's file, it is simple:

1) The constraint activities occupy max time slots does not have all 8 needed activities, but only 7. However, this correction does not make the file solvable.

2) Try to generate, then stop and look at the current or highest timetable. You will notice immediately the problem. This is a good trick to use in the future.

Also, in the future please do not add activities which are split into more components than the number of days per week.

[anisanjum]

Yes Liviu Lalescu Sir,
I have tried this also.
I got the problem too.
The problems are the same which were above mentioned by me earlier.
So please give any solution which could generate my TT.
I have given u my dataset also. 

[Liviu Lalescu]

I meant that the solution is in point 2) from my previous answer. Just do that and you will see.