Retain generated time table

[hipl]

Hi

Each time a file is opened in FET and time table is generated a new time table is generated, is there a option to retain the time table generated
Ex: When for the first time the time table is generated, Teacher X has Maths class on Monday 2nd and 3rd hour, few modifications with respect to other teacher Y was required for which modifications were made and a new time table was generated, but now Teacher X has Math on 3rd and 4th hour..
How do i retain teacher X time table?

[Volker Dirr]

i highly don't recommend to do that.
but you can do that if you want.
just open the generated fet file from the fet-result directory.
here are all activities locked in (generated) time and room.
please genenrate first (that just take a second or two).
then you can add one (or more, but i don't recommend) constraints.
now you will see that (in most cases) is is impossible to generate, because FET/you want to keep all old times!
so you need to "unlock" a few time. as you said you want to "retain", but that is (in most cases) imossible. so you must tell fet some hours that can be different.
do that by fet->timetable or fet->lock/unlock.
but don't forget: this is in most cases a very bad style. do that only if you are very high skilled in timetabling.

[hipl]

Thanks for reply

The situation is say i have started my academic year for 2013-2014 the time table is generated and as per that the classes are conducted but in the middle of year there are changes in the time table for few teachers, so if i make changes and again generate all the teachers time table will be modified which should not happen, it should only modify the ones which are required..

What do you suggest in this case??
Thank you

[Volker Dirr]

that is depending on your dataset:

1.
if you have a very very easy dataset, then you can try the trick i wrote in the last post. just unlock the few teachers and keep all others locked. then generate again. but this will work only with very very easy timetables.

2. if you have an not too difficult timetable and you know that "problem" already a half year before, then you should care about that problem the next time already at the beginning, because it is much easier then! please read chapter "Add a fortnightly activity" http://www.timetabling.de/manual/FET-manual.en.html#id_36 (Just replace every "every second week" by "every second half year". the problem and solutions are the same)

3. if you have a normal/difficult timetable:
totally regenerate. so (nearly) no looked activities at all!
there are a few exceptions: maybe you have normaly only school up to hour 6. there are only a few activities at hour 7 and 8. So i understand the the students already planned their "out of school activities" already and it is bad if school change that.
so exception 1: maybe lock the evening activities (don't forget: only if you have a few. it is nonsense to lock them, if all students always must stay also at hour 7+8!

think about the teachers:
it doesn't matter if the teach math monday 1 hour and english monday 2 hour in the first half and if he swap that activities in the second year, because the working time doesn't change by that.
of course a teacher that has free in the last periods is lucky and want to keep that. other teachers don't have free the last periods, but they also like to have free the last periods. so why keep that fixed? normaly there is no reason for that.
so overall: ask each teacher if he need to keep this free periods (that he got by luck last time!). if he just have reasons like "i like that", "it is nice", ..., then it no reason, because other teachers also like to have it that way! so real reasons are only reasons like "i already planned my consultation at the doctor" or "i already employed the nanny for the other days".
so in normal case only teachers that have free days have reasons like that.
if your timetable is not to difficult, just only fix the free days (by teacher not available). if you have a very difficult timetable, then ask each teacher for a reason!
i highly recommend to not fix other free periods (like Friday last 2 hours), because that teacher got that periods only free by luck last time and other teachers also like to have that! So you should have reasons if you lock that!
so exception 2: lock free days if there is a reason.

[hipl]

Thank you.. ill look into it...

[sparkiemj]

Dear Liviu,

Once again I bother you for your valuable input and advise for a similar matter. Ok I understood your logic behind the changing timetable every time even old data file is loaded so FET will generate new time-table.

However, as I mentioned in my mail earlier, there is one small (or rather big for the teachers) a problem that I am still facing. See for eg. in attached FET file, what we are having is some teachers who are having continuously all periods full on some days while on others they have many free periods. How does one distribute these free periods a bit more evenly.

Another issue often occurs is of same teacher having continuous periods in a class (okay for this I presume that the option about keep contiguous when adding activity is not ticked, then hopefully such problem will not arise - but then again we have some situation, where we are adding some extra periods - eg. say - a teacher has already 6 periods in a 6 day week. Now we decide he needs 1 or 2 more periods in that class, so we add it as another activity, but the problem is that it FET will now sometimes schedule activities for the teacher sometimes together - thus if a maths teacher has 7 periods, then sometimes the teacher will have both periods clubbed together (probably FET considers them as 2 different activities).

So basically, we want to avoid 2 situations -
1) Same teacher should not have continuous periods for either same subject or different subjects in the same class (maybe teacher teaches Maths and Physics in the same class, but we want to avoid having 1 period of maths immediately followed by Physics or vice-versa). Also we don't want a teacher to have 2 Maths periods continously.
2) We also want to have rest or free periods for teachers distributed more evenly through the week. at present in most of the generated timetables that I get, there is always a problem for some teachers who have some days with continous all periods while on some days they have too many rest periods.

I am attaching FET file. Please look into this and help with your suggestion to avoid similar situation as otherwise lots of rework is required for modifying it manually ..  :-(

[Liviu Lalescu]

There are a lot of constraints to use:

1) Teacher(s) (activity tag) max hours continuously, min gaps between activities;
2) Teacher(s) max gaps per day/week, max/min hours daily.

[sparkiemj]

Dear Liviu,

Thank you for your blazing fast reply. However, I am a bit stumped at the options and their usages. Could you perhaps give me an example.

thanks

[Liviu Lalescu]

I am not sure how could I describe better, I hope other users will answer better than me here.

1) You can add max hours continuously for teacher(s), or max hours continuously for a teacher and an activity tag (add the same activity tag for the involved activities). Or you can add min gaps between activities, which applies if the activities are in the same day.

2) I cannot add more words to this - just that gaps and min hours daily should have weight 100.0%, because of the algorithm.

[sparkiemj]

I am not sure how good it will work as there is a minor issue here. A teacher should not have continuous periods with a class (esp. if they are teaching same or different subjects) but the constraint does not seem to work. :-(

i am stuck .. seems will have to just edit the html file in excel manually and fix the problem !!

[sparkiemj]

oh by the way, I noticed - min hours daily does not exist in my menus .. its only max hours daily or max hours with an activity available as an option !!

[Liviu Lalescu]

oh by the way, I noticed - min hours daily does not exist in my menus .. its only max hours daily or max hours with an activity available as an option !!

That's impossible. I just checked - latest version on my hard disk, GNU/Linux, see teachers' time constraints, entries 8 and 18 (under those with icons).

[Liviu Lalescu]

I am not sure how good it will work as there is a minor issue here. A teacher should not have continuous periods with a class (esp. if they are teaching same or different subjects) but the constraint does not seem to work. :-(

i am stuck .. seems will have to just edit the html file in excel manually and fix the problem !!

No, no manual fixing, we need to get this going :-)

Either: add all involved activities into a constraint min 1 gaps between activities, or add the same activity tag to all the involved activities, and use teacher max hours continuously with an activity tag. The involved activities are all the activities of that teacher with that class. It has to work.