Re: [rules-users] Hard constraints to enforce employee seniority

** Op 07-12-11 21:41, Patrik Dufresne schreef: Hi all, I'm trying to create rules to model my problem. So far, I didn't manage to create rules to make Drools converge to a solution because of score traps. I don't see any way to avoid it (as I'm not an expert with Drools). I can express the rule as follow : a senior employee should work before a less senior employee. I've implement it as a hard constraint : rule "hard-Seniority" when $employee : Employee() $assignment : PlanifEventAssignment( $planifEmployee : employee ) What's does this $planifEmployee do? not PlanifEventAssignment( employee == $employee ) eval(Helper.compareEmployee($employee, $planifEmployee) < 0) then insertLogical(new IntConstraintOccurrence("hard-Seniority", ConstraintType.NEGATIVE_HARD, 1, $employee, $assignment)); end The function Helper.compareEmployee(e1, e2) return -1 if e1 is more senior then e2 (mostly based on hire date and other boolean fields). On first sight, in Solution.getProblemFact() I would add these cached problem facts, for any 2 employees (but just once per combination): new EmployeeRanking(higherRankedEmployee, lowerRankedEmployee, numberOfEmployeesInRankBetweenThem) then you can do rule "hard-Seniority" when EmployeeRanking($higherRankedEmployee, $lowerRankedEmployee, $numberOfEmployeesInRankBetweenThem) PlanifEventAssignment(employee == $lowerRankedEmployee) PlanifEventAssignment(employee == $higherRankedEmployee) then insertLogical(new IntConstraintOccurrence("hard-Seniority", ConstraintType.NEGATIVE_HARD, $numberOfEmployeesInRankBetweenThem, $employee, $assignment)); This way, the rule make sure a senior employee is working. But it's a score trap since, many moves are required to resolve the constraint. e.g: PlanifEventAssignment1 = e2 PlanifEventAssignment2 = e3 PlanifEventAssignment3 = e4 PlanifEventAssignment4 = e5 e1 is not working. Multiple move are require to reach the best solution : PlanifEventAssignment1 = e1 PlanifEventAssignment2 = e2 PlanifEventAssignment3 = e3 PlanifEventAssignment4 = e4 So I'm asking you. What is the best way to make Drools converge ? Do I need to change my rule, or should I create a BigMove ? course grained moves will work mostly, but solving the score trap itself is a far better long-term solution (and it still allows you to add course grained moves later). -- Patrik Dufresne _______________________________________________ rules-users mailing listrules-users@lists.jboss.orghttps://lists.jboss.org/mailman/listinfo/rules-users -- With kind regards, Geoffrey De Smet _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users