Need a custom version

Started by YOUSSEF HOUIET, May 19, 2020, 07:04:55 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


Hi Mr. Liviu
Thank you for this useful software and for accepting our suggestions.

I use fet software to schedule exam supervision,

To solve the problem of repeating teachers in rooms, I adopt the following method:

I consider exam periods as fet Days

I consider the real rooms as fet Hours.

For example: I have 4 rooms R1 R2 R3 R4 and the last room R_RESERVE is used for the activities of reserve teachers

To prevent  repeating teachers in the rooms, I use the constraints :
a set of activities occupes max time slots from selection

I choose the activities of a teacher and then I choose the R1 hour on all days and put  1 in max occupied value
Same constraint with all R2 R3 R4 hours
I repeat the process with all the teachers.

Except for the last hour R_RESERVE used for reserve teachers, where we dont add this constraint

Unfortunately, the problem is the large number of constraints of this type
(Number of constraints =number of teachers x hours x days)

To solve this problem is there a possibility to add these  constraints implicitly in a customized version that ensures that each of the teachers work in each of the R1 R2 hours... Only once a week?

Except for the last hour R_RESERVE of each day, which is used for the activities of reserve teachers, which can be assigned to the teacher more than once during the week

I attached a picture of the explanation, a demo file and pictures of the result.

Benahmed Abdelkrim

عزيزي يوسف؛
يمكن حل الإشكالية التي طرحتها بواسطة النسخة المخصصة
بكل سهولة كما هو مشروح في الرابط التالي

وذلك بإدخال 5 غرف(قاعات) كمدرسي فيت
والمدرسين الحقيقيين كغرف(قاعات) فيتيبدو من الصور أن لديك 40 نشاطا موزعين على 10 مدرسين و 5 قاعات. أليس كذلك؟
سأحاول إنتاج ملف فيت وأرفقه هنا، إذا كان هذا ما تريد بواسطة النسخة المخصصة

Dear youcef
You can solve the problem you presented with the custom version
Easily as explained in the following link

by entering 5 rooms as teachers FET
And the real teachers as rooms, so it seems from the pictures that you have 40 activities spread over 10 teachers and 5 halls. is not it?
I will try to produce the file. fet and attach it here, if that is what you want with the custom version

Benahmed Abdelkrim

Here is the file after it was produced by

Liviu Lalescu

Hello, Mr. Youssef Houiet,

1) Your file does not contain the constraint for T10 R1?

2) Do you mean you need to input (Number of constraints =number of teachers x hours) constraints?

3) I think I can do this for you. So, hard-coded that each teacher has at most a single activity at the same hour from each day? I will begin working as soon as you confirm. May I call this version "FET-Houiet", or do you propose another name?

4) Benahmed, yes, we made a different custom version, but the two versions can coexist. However, I think that Benahmed's version is a bit better in allowing constraints for the real teachers, max hours daily and max span per day.


Thank you for your quick response.
1. I think I missed  adding the constraint for the T10 R4

2. I mean input implicit constraints :
Number of restrictions = (number of teachers) X (number of hours-1)
The last hour (the last real room) is excluded because it is used  to put the activities of the reserve teachers
And it may be assigned to the same teacher more than once.

If the last hour exception clouse is hard-coded, then can be abandoned or not respected, and input the constraints for all teachers and hours,

and i will use more hours to the reserve activities, instead of using one

3- I think that  this method is better too because :
allocation activities to real teachers allows and facilitate  adding other time constraints like min days between teacher activities, tags(of teachers) are not overlapping, ...

4-for the name of custom version, I have no idea right now.
You can call it by the name that you suggested) FET-Houiet)
Thank you for your response and your help.

Liviu Lalescu



Thank you, Mr. Liviu, for accepting my demand.

The version works well with the example file that was previously provided,

But I think there's a problem.
When I use another file and i try to generate I get an error

I attached the file that produces the error

Liviu Lalescu