All,

I have a problem where I need to assign tasks:

1.) Times

2.) Resources based on a Resource Type

I've used the nurse rostering problem as an example and come up with a planning entity ResourceAssignment that looks like:

Facts:

Task

ResourceType

Variables:

Time

Resource

For example:

1.) Lets say there are two resource types Type1 & Type2

2.) A pool of resources: Resource1(type1), Resource2(type1), Resource3(type1), Resource4(type2), Resource4(type2), Resource5(type2) ...

3.) Task A: that requires 1 resource of type1 and one resource of type2

My program creates two PlanningEntities

ResourceAssignment1

Fact:

Task=A

ResourceType=1

Variables

Time

Resource

ResourceAssignment2

Fact:

Task=A

ResourceType=2

Variables:

Time

Resource

I've created a rule that is designed to keep tasks starting at the same time:

//tasks need to be in the same timeSlot

rule "taskInTimeSlot"

when

$ra1 : ResourceAssignment ( task != null, time != null, $id : id, $task : task, $time : time)

$ra2 : ResourceAssignment ( task != null, timeSlot != null, id != $id, task == $task, time != $time )

then

insertLogical(new IntConstraintOccurrence("taskInTimeSlot", ConstraintType.NEGATIVE_HARD,

                1,$ra1, $ra2));

end

*PROBLEM*

This results in: Cancelled step index (7), time spend (2848): there is no doable move. Terminating phase early.

If I change the constraint to a NEGATIVE_SOFT the problem is solved, but it doesn't scale. Any more that a few tasks and it doesn't seem to be able to find solutions.

What I need is for swaps and moves to change the time on multiple ResourceAssignments together.

Am I going about the problem the right way? Do I need something other than the generic move/swap factories?

Thanks in advance,

Jason

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