Problem generating timetable???

[nikma]

Hi, i'm not sure if I have given the right constraints and the generating process stops from the beginning
1. I have some teachers with a certain activity (let's say ENG) 10 hours (5*2hour activity) and I want  this activity to start at first period. I have put activity constraint "An activity has a preffered starting time"
2.I have some teachers with the same activity (let's say ENG) 8 hours (4*2hour activity) and I want this activity to start at first period. I have put activity constraint "An activity has a set of preffered starting times"
3.I have some teachers with the same activity (let's say ENG) 7 hours (3*2hour activity+1hour) and I want this activity to start at first period. I have also put activity constraint "An activity has a set of preffered starting times"
May be I'm wrong so far but...
4. The same teacher has also other subjects (such as SPORTS let's say 3 hours, MUSIC 3 hours etc) but in order to help the program generate the timetable with more...freedom, I have assigned activities with 1 hour duration with the same name let's say SUBJECT1. So teacher1 have 10 hours ENG and the rest 10 hours SUBJECT1 -with 10 different 1hour activities-and NOT SPORT 3h, MUSIC 3h etc  (total 20 hours for teacher1 per week)
Am I wrong with this approach. It seems to me an easy timetable but I have no results...
I would appreciate if you help me...
thnx

[Volker Dirr]

About 1 to 3:
I guess you talk about many activities. In that case you should use time constraints -> activities -> a set of subactivities have a set of prefferd starting times.

About 4:
Your idea is nice, but to dangerous, because you don't care about sport room conflicts.

About "no results" and "generating process stops from the beginning".
What does FET complain about? You need to fix that first!

If you still have problems: Difficult to halp without your dataset. Maybe sent it.

[nikma]

First of all, thank you for the immediate response.
It's getting much better now but I still have problems generating the timetable (311/335 activities in an hour but I don't think it will be a better score). If I increase the "max gaps per day for all teachers" from 2 to 3 or 4 then the score is 323/335)
Regarding 4 in my previous post, i don't have to worry about rooms (no assignments regarding space).
If you are so kind to take a look at my dataset, I would be very glad.
If there's a problem with the language, please tell me...
thank you in advance...

[Volker Dirr]

Looks like you sent me an old dataset. It's solveable, but there are only 297 activities in that dataset. Not 335.

[nikma]

Looks likes you are right...(5:00 a.m is not a good time for work :-(
I resend the new version...
I'm sorry...

[Volker Dirr]

ah. ok. It's a problem of a combination of several constraints.

you have a few min n day with 95%. if you lower them to 0%, then you will see that your dataset solve with max gap per day = 3 in less then a few seconds. So it's possible to solve with gaps = 3.

So what to do?
I recommend this: Set max gaps per day = 3.
Then think once again about that 95% weight constraints.
If you like to have them, increase them up to 100%. (yes, this maybe make the timetable impossible, but it's easier to find bugs this way!)
If it doesn't matter at all: decrease them to 0%.

If the timetable stucks, then check the number of placed activities and the "view initial order of placing activities" while generating. Now remeber the "problematic" activity. So if fet is able to place 323/355 activities, then remeber activity 324 (be carefull, this is NOT the activity id!)

Now stop generating/sumulating and view the timtable. Try to place that problematic activity yourself into the teachers timetable. You will see it is impossible. Now think: Why is it impossible? (For example: Teacher is not available to many days/hours, ...) Now remove the "problem". (In "worst" case a min n day. Or modify that activity (i mean the "problematic" activity (see generating/simulation) AND/OR the "problematic" activity (see timetable); Split into a lower number of parts and increase the duration of the activity. Or ...)


(by the way: solve with max gaps per day = 2 if all min n day will be very difficult. even reducing all min n day down to 0% is still very difficult (impossible?). If you want to have max gaps = 2, then you also need to remove other  constraints (like reomoving some teachers not available constraint). You must decide which constrainit is needed more.)

[nikma]

Thank you so much for the guidelines!!!
You've helped me soooo much!!!
Now I have realised what the problem is... It was not an easy timetable (I supposed to be) with all these constraints especially with max gaps=2...
But now, I know how to face it up...
I thank you once again for the time you spent for my  case...