"Ideal" time to solve

[pg788]

How long should I wait before stopping a simulation? If the timetable hasn't solved in say 5 minutes or so, is there any hope for it or should I stop and relax the constraints?

[Bobby Wise]

It depends I think. I've had tt's generate overnight. Go home come back in the morning and it's there for you.


What has bothered me is I'm not sure if the generation continues if the pc goes to sleep or into hibernation mode. So I always set my power saving off and just let FET do the rest.

[Liviu Lalescu]

What has bothered me is I'm not sure if the generation continues if the pc goes to sleep or into hibernation mode. So I always set my power saving off and just let FET do the rest.

I am sorry, but I don't know.

[pg788]

Thanks, Bobby Wise! How many activities were you placing?

Maybe a better question is, I have 258 activities out of which around 175 have been placed within the first five seconds, but after that, there has been no progress in the next 2 minutes--should I wait for it to solve further. I'd expect that a small number of activities should be placed rather quickly; if the software is taking time, it might indicate there is a problem.

[Liviu Lalescu]

I think there is no need to wait further.

[pg788]

Thanks, I will try to modify the constraints.

[Volker Dirr]

is you "see" that the number of placed activities always go up and down around maybe 10 activities in a few seconds/minutes, then all is fine. FET is still searching. Don't worry, it will (hopfully) find a solution, but it might take long time.
if you "see" that the number of placed activities suddenly didn't go up and down anymore; it suddenly go down only (or just toggle between +/-1 placed activity); then wait a bit. If you see that behavior several time (depending on your dataset maybe a few seconds or a few minute), then there is a bug in your dataset. FET will never find a solution then, since it is impossible to solve the dataset. Sadly FET can't "see" that. It is a bit tricky to learn to understand that bugs, but don't worry: you will learn that too. As soon as you understood that it will be (in most cases) very easy to understand that bugs and to fix them.

[pg788]

It is placing 200--220 activities within the first 2 seconds, but then nothing changes for the next 5-7 minutes. So I guess it's more likely there is a bug in the data.

[Liviu Lalescu]

It is placing 200--220 activities within the first 2 seconds, but then nothing changes for the next 5-7 minutes. So I guess it's more likely there is a bug in the data.

Indeed.

[Volker Dirr]

publish your fet file or sent it by email if you can't find your bug.

[pg788]

Thanks! The bug got detected and squashed  Will send you the file if I run into any other problem again!