[rules-users] problem in firing dependent rules..

[Sudhir M]

Thanks Edson  for a quick response.
Actually our requirement is to have our own custom rule builder which will
use drools as a rule engine behind. So we are using Drools API to create the
drl. since the end-user who models a rule is a business guy it is difficult
to ask him to manage the dependencies. In this case it may not be possible
for us to know when to update a fact. Initially we were by default adding
modify() block to update the facts for every rule. In this case if more than
one rule is eligible to fire then its going into a loop firing all the rules
again and again in a loop. Is there a way we can handle this requirement.
Below is the sample rule that we created which ran into loop through drools
API
rule "PolicyTierClassification"
 no-loop true
 when
healthInsuredbindings : HealthInsured( weight >= 285 , weight < 327 , height
== "6ft 6in" , gender == "Male" )

 then
modify(healthInsuredbindings){setPolicyTier("Standard II")};
list.add("To determine tier based on insured gender, height and
weight(weight>=285 , weight<327 , height==6ft 6in , gender==Male ) ->
(PolicyTier = Standard II)"); end



On Fri, Jan 9, 2009 at 8:27 PM, Edson Tirelli <tirelli at post.com> wrote:

>
>    Sudhir:
>
>    In Rete, you must tell the engine a fact has changed, either by using a
> modify() block (recommended), or update() or property listeners.
>
>    LEAPS is a different algorithm that was originally maintained by a
> community user that long ago abandoned it. It is no longer included in the
> drools distribution.
>
>    []s
>    Edson
>
> 2009/1/9 Sudhir M <sudhir.cse at gmail.com>
>
>> Hi All,
>> I don't know whether I have encountered a strange problem or my
>> understanding of drools is wrong.
>>
>> I have 3 rules out of which two are dependent. Between the dependent ones
>>  one rule makes the other rule eligible to fire but I don't know why the
>> dependent rule is not firing. Below are the rules I have written.
>> package com.valueMomentum;
>> import com.valuemomentum.eligibilitymodel.oo.*;
>> import java.util.ArrayList;
>> global java.util.ArrayList list;
>>
>> rule "PolicyTierClassification"
>>  no-loop true
>>  when
>> healthInsuredbindings : HealthInsured( weight >= 134 , weight < 157 ,
>> height == "4ft 10in" , gender == "Male" )
>>
>>  then
>> healthInsuredbindings.setPolicyTier("Standard I");
>>
>> System.out.println("PolicyTierClassification");
>> list.add("To determine tier based on insured gender, height and
>> weight(weight>=134 , weight<157 , height==4ft 10in , gender==Male ) ->
>> (PolicyTier = Standard I)"); ;end
>>
>> rule "AlcoholConsumptionClassRule"
>>  no-loop true
>>  when
>> healthInsuredbindings : HealthInsured( alcoholConsumptionFrequencyPerWeek
>> == "2-3" )
>>
>>  then
>> healthInsuredbindings.setAlcoholConsumptionClass("B");
>>  System.out.println("AlcoholConsumptionClassRule");
>> list.add("To derive the alcohol consumption class based on consumption
>> frequencyalcoholConsumptionFrequencyPerWeek==2-3 -> (AlcoholConsumptionClass
>> = B)"); end
>>
>>
>> rule "UnderwritingFactorRule"
>>  no-loop true
>>  when
>> healthInsuredbindings : HealthInsured( alcoholConsumptionClass =="B" )
>>
>>  then
>>  healthInsuredbindings.setUnderwritingFactor(1);
>>  System.out.println("UnderwritingFactorRule");
>>      list.add("To derive UnderwritingFactor from
>>  alcoholConsumptionClass==B -> (UnderwritingFactor = 1)");end
>>
>> this my initial fact HealthInsured healthInsured = new HealthInsured();
>>  healthInsured.setAge(25);
>> healthInsured.setGender("Male");
>>  healthInsured.setWeight(140);
>> healthInsured.setHeight("4ft 10in");
>>  healthInsured.setTobaccoUser("No");
>> healthInsured.setMotorcycleRider("No");
>>  healthInsured.setRelationToInsured("Insured");
>> healthInsured.setUnderwritingFactor(0);
>>  healthInsured.setPolicyTier("Preferred");
>> healthInsured.setAlcoholConsumptionFrequencyPerWeek("2-3");
>>  healthInsured.setAlcoholConsumptionClass("A");
>> Based on the above fact PolicyTierClassification, AlcoholConsumptionClassRule
>> are eligible  to fire. AlcoholConsumptionClassRule  is setting a property
>> alcoholConsumptionClass to B based on which UnderwritingFactorRule rule
>> becomes eligible fire but in this case the dependent rule is not firing. I
>> think we can use update in  AlcoholConsumptionClassRule  but I think if
>> we have to manage those dependencies it will be more error prone and the
>> results are might be more inconsistent.
>>
>> I have tested it Using RETEOO in drools 3.x and 4.x which yields me the
>> same results. But when I used LEAPS algorithm then i even got the dependent
>> rule i.e UnderwritingFactorRule  rule  also fired.
>>
>> Thanks in Advance,
>>
>> sudhir.
>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
>
> --
>  Edson Tirelli
>  JBoss Drools Core Development
>  JBoss, a division of Red Hat @ www.jboss.com
>
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>
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