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Op 01-12-11 01:53, Patrik Dufresne schreef:
<blockquote
cite="mid:CAJ=kj5yKk1Yo+36fmUpjn9W5280b=-Z+6waP5eYOUiQw6WBNwA@mail.gmail.com"
type="cite">Hi,
<div><br>
</div>
<div><span><font color="#222222" face="arial, sans-serif" size="2">I
am a Java developer and I am currently working on a work
force management software for food compagnies. So far, I've
decided to use constraint programming (CP) to find a
solution to the problem. The current version is using JaCoP
as a solver, but I find it hard to make it support
soft-constraint and it only use Depth First search. So I'm
looking </font><font color="#222222" face="arial,
sans-serif">around</font><font color="#222222" face="arial,
sans-serif" size="2"> for a different solver engine and
Drools Planner seams to fit my need. I'm just concern about
it's speed since I don't see any way to add global
constraint (like all-different, Count, Among, etc.)</font></span></div>
</blockquote>
Those global constraints break down into simple score rules, in an
Object Orientated manner (instead of twiddling with primitive
arrays). For example:<br>
<br>
all different:<br>
Assignment($x : x)<br>
not Assignment(x == $x)<br>
<br>
Through ReteOO and rule engine forward chaining, these are made fast
and scalable with indexing, incremental score calculation
(=delta's), ...<br>
<blockquote
cite="mid:CAJ=kj5yKk1Yo+36fmUpjn9W5280b=-Z+6waP5eYOUiQw6WBNwA@mail.gmail.com"
type="cite">
<div><span><font color="#222222" face="arial, sans-serif" size="2"><br>
</font></span></div>
<div><font color="#222222" face="arial, sans-serif">I've look
closely to the nurse rostering example. My problem is very
similar. Let say, I have 150 nurses, ~42 different skills, 9
shifts, ~300 events to be assigned. Whats make it easier
compare to the example, I only need to plan one week. My
question is simple, does Drools will be able to handle it ?</font></div>
</blockquote>
Yes. Planner is used successfully in far greater problems sets than
this :)<br>
Assigning 300 events is really not much: most of the examples
already have 1000-5000 planning entities to schedule (to multiple
variables sometimes, while nurse rostering only has 1 variable, the
nurse).<br>
<blockquote
cite="mid:CAJ=kj5yKk1Yo+36fmUpjn9W5280b=-Z+6waP5eYOUiQw6WBNwA@mail.gmail.com"
type="cite">
<div><font color="#222222" face="arial, sans-serif"><br>
</font></div>
<div><font color="#222222" face="arial, sans-serif">To give a
better understanding of the problem I'm trying to solve, I've
attach a PDF document with more explanations. (<a
moz-do-not-send="true"
href="https://docs.google.com/open?id=0BykkHu_UReIvYzg3NmM2YmUtYjVhNy00NjgwLTliNjctNWJjZTMyNjU0MDM2">https://docs.google.com/open?id=0BykkHu_UReIvYzg3NmM2YmUtYjVhNy00NjgwLTliNjctNWJjZTMyNjU0MDM2</a></font><span
style="color: rgb(34, 34, 34); font-family: arial,sans-serif;">)</span></div>
<div><font color="#222222" face="arial, sans-serif"><br>
</font></div>
<div><font color="#222222" face="arial, sans-serif">Thanks to post
your opinion. </font></div>
<div><font color="#222222" face="arial, sans-serif">Any tips are
welcome.</font></div>
</blockquote>
Once you've got the Planner implementation working well, benchmark
it against your JaCoP results and blog/tweet them :)<br>
<blockquote
cite="mid:CAJ=kj5yKk1Yo+36fmUpjn9W5280b=-Z+6waP5eYOUiQw6WBNwA@mail.gmail.com"
type="cite">
<div><font color="#222222" face="arial, sans-serif"><br>
</font></div>
<div>-- <br>
Patrik Dufresne<br>
</div>
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
With kind regards,
Geoffrey De Smet</pre>
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