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Hi, everybody:

Still testing and trying to get as much as possible from FET. I have another question. Maybe someone nicely can help me save some time. Fingers crossed.

This is the issue. We have a room, let's say A4, which we want to be the prefered room for spanish language from all groups and years. The problem is the overall number of hours is greater than the 30 hours available weekly in this room.

My appropach. I added a constraint for the subject in each year to assign A4 as prefered room with 99% weight. Then for the same each subject, I added a 100% set of prefered rooms for those subjects. My thought was, ok, try with A4 and if not possible, use one room in the prefered set. The problem is it seems to really make the process very slow, specially when adding other constraints or trying to make some harder to get. I tried to lower the weight to 90% and it really seems to improve the time of generation, and get almost same results as with 99%, but still slow when adding more constraints.

So, I wonder, maybe is there a way that I still didn't think of doing the same thing, and get similar results without using the prefered room with a weight under 100?

Thanks in advance to everyone interested in this.

Hi, again:

Liviu, I tried with the activities occupy max time slots from selection constraint. I attached 2 of them to each teacher with two occupied slots out of three in each of them, and I managed to generate the timetable in half an hour, more or less. That is really great news. Now I will try to make one hour of the two choices be the same, to increase the probability of being selected, but I am not sure if that will have the desired effect, what do you think about it?

Well, the effect is not exactly the same as what we were looking for for seting preferences from 1 to 4, which can be done with the prefered times for an activity with weight under 100% but this last option really seems very time demanding when generating the timetable, as you suggested. But it's a good solution anyway.

One last thing. I think I start to understand that as much as you use weights under 100% the process can become very long... am I right? Is it always better to use constraints with 100%?

Thank you very much, Liviu, for your help.

Hello Liviu:

Thanks once again. As soon as I have a little more of time I will check all the options you suggested, including the last one. I am focusing right now in trying to make the timetable as compact as possible testing the min. hours per day for teachers and the max gaps. Just seeking the limits of hour timetable against generating time.

I was testing with the ordered preferences yesterday but the times of generation were going too high. So I decided to focus in making the timetable as compat as possible first and then will try the second and third options you told me about.

I will be posting the results here.

Hi, Liviu:

After this your explanation, I think I do understand now what the second option does. But, is it neccessary to use the other time restrictions in the second file, the min number of days between activities set to 95%? and the prefered times for a set of activities from the first option? I mean, would it be enough to use the last restriction of this second file you sent me?

And also, would it be a lot time consuming to use this restriction twice over the same teacher, let's say choose 4 slots of the end of the day and you'll get one for sure and also do the same with another alike constraint for the beginning hours?

By the way, thank you for your attention... I really appreciate it.

Hi, Liviu:

The first approach you suggested I can undestand. It's the clean and neat way to do it without twisting things as I did with creating extra activities. Well, I have added for only one teacher, and it is quite slower than without these restriction... so maybe you are right about time.

The second approach I still don't understand well. I will check if first one works and whether it does or not, I will have a look carefully at second option. I want to fully understand it too. But since you say you can't have preferences, this wouldn't match the need of teachers asking for a specific free hour, right?

Hi, I am quite new at FET. For the last month I have been trying to learn the software and to generate timetables for the high school I am working at the moment. The aim is to use FET in the future and get rid of the software they used until now which is only working for windows and for some other reasons.

Ok, let's focus:

I have generated a timetable with the data for the current school year with FET. And I have quite succeed. Also enjoying the process )) All is fine, I made categories for multiple activities in same time slots, added rooms, control not full time teachers and make timetables with a max nº of week gaps of 2!!! which is something great.

But (there's always a but?), there is something I can't figure out. In the region where I live, almost every school use the same timetable generator software (comercial) and there is something they are very used to. They allow teachers to choose 4 time slots along the week prefered to be free, ordered from first to 4th option. For example to finish sooner a specific day or start one hour later another day. Obviously, not all the teachers at the same time can be free the same hour. So I have been thinking how to do it with the constraints FET offers.

My first try was using the not available teacher's periods, but the restriction must be 100% weight, and that doesn't math the needs.

So I decided to create 4 different subjects OFF1, OFF2, OFF3 and OFF4 and then I made the match the right period according to each teacher free preferences with the an activity has a prefered starting time, which allow me to give 90% to the OFF1 activities, 80% to the OFF2, 70% to the OFF3 and so on. The problem is that when FET couldn't allocate the activities at the right slot cause of other contraints and coincedences in teachers preferences, It allocates them in any slot, creating more real gaps in timetable. Then to avoid that, created a new tag for activities called FREE, and added a restriction to force these activities to be allocated at the 1st and last periods of each day of the week with 100% weight. The result, 10 hours FET trying :/  Oh, I forgot to mention that the max gaps per week is also set to value 2.

And I totally ran out of ideas. So I please ask you for help if anyone has a good neat idea to solve this issue and let add teachers free period references this way, before my old computer starts burning. I would really love to get it work, cause I really believe this software is good.

Thanks in advance.