Re: Crossover in Scheduling GA

> I'm not really clear on your constraints or your fitness function. Can 
you change an activity's duration?  Is the problem oversubscribed (more
activities than you could possibly fit into your time frame)?  Can two
activities run simultaneously (multiple resources)?

For right now, activity durations cannot be changed. The time frame can/will extend to cover the total duration of the activities, so that shouldn't be a problem. We won't run things concurrently (if we need to do that, activities can have a "unit" element [first unit/second unit] so we'll only schedule activities from one unit if that's a criterion).

> Or you may be 
dealing with something more like a job-shop problem where you're trying
to minimize the total time for all the tasks (given multiple
resources).

Exactly. There will be priorities for keeping certain elements the set of activities together (activities with the same location, for example). I'm assuming I would put this in the fitness function.

Ordinarily the constraints you mention (night/day, day of week, etc.)
can be covered using time windows.  It's all a matter of what your
schedule will look like.  Is it a week's worth?  A month's worth?  A
year?

The time varies - assume 6 weeks to six months, depending on the number of activities to schedule.

Sounds like a fun problem; I'd just like some more details.

One other big question I have is the necessity of encoding the element information. If I simply create a series of activity objects, containing one or more element objects, and each of those elements undergoes some sort of test, is that going to blow the speed all to h***? If so, are there references to some of the more common encoding systems out there? I wonder if it's possible to "pre-compile" the encoding?

Hope this helps clear up the confusion. Sorry for the delay in replying - we've been stuck coding up here in the salt mines.

Jim Stanley

.