Main Menu

Time...!

Started by Benahmed Abdelkrim, February 25, 2017, 04:26:32 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Print
Go Down Pages1 2
User actions

Benahmed Abdelkrim

February 25, 2017, 04:26:32 PM
 Hi!
    Can we say that at some time past FET has failed to find a solution?

An open question to everyone...
B.A/krim

Liviu Lalescu

#1
February 26, 2017, 11:08:06 AM
There are two files in the official FET examples which can solve in 3 minutes or in 5 hours (on my computer). The files are examples/Namibia/by-Bobby/set-2/may-take-hours/CONCORDIA.fet and examples/Romania/Oradea/FS-2008-2009-difficult.fet.

Also, some users reported more than 24 hours for a file.

Benahmed Abdelkrim

#2
February 26, 2017, 05:42:36 PM Last Edit: February 26, 2017, 05:45:25 PM by Benahmed Abdelkrim
May be the following constraints that are at issue:
1/ same starting time with 100%
2/ min days between activities with 100%

I think the first one(same starting time) needs better optimization, maybe, I do not know ...what do you think?



B.A/krim

Liviu Lalescu

#3
February 26, 2017, 05:45:52 PM
I am not sure I understand, but I can tell you that they are optimized the best I could.

Benahmed Abdelkrim

#4
February 26, 2017, 05:50:56 PM
 mmm... May be the weight 100%?
B.A/krim

Liviu Lalescu

#5
February 26, 2017, 05:52:30 PM
You can use weight less than 100%, but the constraint might then be broken.

Benahmed Abdelkrim

#6
February 26, 2017, 06:04:34 PM
In this case the conflicts will be near and the production time will be reduced. But the quality will be reduced too!
Can the production time be reduced with a better quality of a timetable?!

B.A/krim

Liviu Lalescu

#7
February 26, 2017, 07:55:57 PM
Quote from: Benahmed Abdelkrim on February 26, 2017, 06:04:34 PM
In this case the conflicts will be near and the production time will be reduced. But the quality will be reduced too!
Can the production time be reduced with a better quality of a timetable?!

I guess the answer is no.

Benahmed Abdelkrim

#8
February 26, 2017, 08:17:39 PM
You mean that we can not avoid conflicts, if we want a reduced production time?
B.A/krim

Liviu Lalescu

#9
February 26, 2017, 08:22:14 PM
It is logical that the generation takes longer if the timetable is more constrained. But in some cases it can take less time. For instance, for a locked timetable, it takes very little.

Benahmed Abdelkrim

#10
February 26, 2017, 08:56:47 PM
Sometimes With the same schedule and under the same conditions of data and constraints, different production times are obtained...
B.A/krim

Liviu Lalescu

#11
February 26, 2017, 08:58:25 PM
Yes, of course, the process is semi-randomized.

Benahmed Abdelkrim

#12
February 27, 2017, 03:18:18 PM
  ...Here an example where FET takes 3H 37Min 55S to produce a timetable
B.A/krim

Benahmed Abdelkrim

#13
February 28, 2017, 05:02:07 AM Last Edit: February 28, 2017, 05:33:13 AM by Benahmed Abdelkrim
Quote from: Liviu Lalescu on February 26, 2017, 11:08:06 AM
There are two files in the official FET examples which can solve in 3 minutes or in 5 hours (on my computer). The files are examples/Namibia/by-Bobby/set-2/may-take-hours/CONCORDIA.fet and examples/Romania/Oradea/FS-2008-2009-difficult.fet.

Also, some users reported more than 24 hours for a file.

  Sory! But you meant that time depends on hardware; Ie that the same file can take diferends times on diferends computers?!!!...
B.A/krim

Liviu Lalescu

#14
February 28, 2017, 07:29:30 AM
Yes.

You can start with the same random seed to obtain the same timetable.
Print
Go Up Pages1 2
User actions