Dolphins schedule

[Paul the dolphin]

In this clear file, none of the kids have any limits, so it should be easy.

[Liviu Lalescu]

Yes, everything seems OK, without a constraint to restrict that teacher (Merel) from any activity. See the attached file, I commented that constraint with LIVIU and I deactivated it.

Also, preferred time constraints without any X are useless (but I think you want to add some X's later?)

I do not understand: "after 3rd any dolphin". I think you mean two dolphins necessary and first dolphin preferred.

Mashi danki?

[Paul the dolphin]

HEy Liviu,


reply's

1. Isnt that weird, that with the adding of the time constraint for merel not working and deactivating it, the scheduling works.

2. Yes I know, this way the other therapist only needs to place x's and put in the names of the children, making it very easy to use.

3. About the dolhins the following. We have a first preference and a second, after that is free for all. Can you explain how it works to me again with the contraints and the preferences?

thanks!

[Liviu Lalescu]

1. Deactivated constraint is equivalent to no constraint added.

3. Therapist Mirte prefers dolphins Bonnie, then if not possible, Nubia, then if not possible, any other from the other three. See attached. Add X with 99% to other three (first constraint), then X with 90% to Nubia (second constraint). The last 90% can be added also to the other three, because the largest value (99%) will win (and adding X to all four is easier for the user). Two constraints.

You can change these values, but Nubia's value (or all four's value, three+Nubia) must be lower than the other three's value.

I hope I am not mistaking.

[Paul the dolphin]

Hey liviu,

I changed all the dolphin preferences as you said, from 100 to 99 and 95 to 90. This results in more undesireable combinations. Any idea why?

[Liviu Lalescu]

Maybe 't4 not preferred' will win, because it is 95%.

Change from 100 (99) to 99.99 or 99.999 and from 95 (90) to 99 or 99.75.

(100-99.999)%=1e-5, in 1 out of 1/1e-5=100,000 cases the constraint will be skipped. This is how FET (approximately) computes.

You can go to 6 decimal digits, if FET still solves the file (99.999999).

[Paul the dolphin]

ok that seems to work. Next week I get the chance to do it together with our managment, lets keep our fingers crossed!