[rules-users] Planner: Hard Constraint Prevents Moves and Swaps

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