[rules-users] Conflict detection problem

[Swindells, Thomas]

An approach that may work is to decouple the suggested results from the model with support for multiple values.
To do this you could define an fact type of Affirmation(String name, Object subject, Object value).
Where the names are a list of well known values.

You rules would then look like the following:
rule "Is Major"
        when
                $a : Applicant (age >= 18)
        then
                insert(new Affirmation("IsMajor", $a, true));
 end

 rule "Is Minor"
        when
                $a : Applicant (age < 21)
        then
                insert(new Affirmation("IsMajor", $a, false));
end

you can then look for contradictions with a rule like the following

rule "contradiction"
        when
                $aff1 : Affirmation()
                $aff2 : Affirmation(this != aff1, name == $aff1.name, subject == $aff1.subject, value != $aff1.value)
        then
                //is both true and false, 3 and 5 etc
end

Obviously there are various way this could be enhanced or done - the affirmations could include the rule name to allow you to pinpoint which ones are producing contradictory results etc. You would also have some lower salience rules to actually populate your real facts with the actual results if a contradiction didn't occur.


Thomas


> -----Original Message-----
> From: rules-users-bounces at lists.jboss.org [mailto:rules-users-
> bounces at lists.jboss.org] On Behalf Of AlisterC
> Sent: 11 March 2011 09:27
> To: rules-users at lists.jboss.org
> Subject: [rules-users] Conflict detection problem
>
> Greetings,
>
> I am working on a collaborative platform project which will contain
> datas,
> informations and knowledges
> such as buisness rules. Consequently, a rule engine is a requisite and
> I am
> testing the Drools suite.
>
> Because a lot of different people will be able to define rules, some
> combinations might be contradictory.
> So the rule user need to know which rules are in conflict, and
> eventually
> choose the ones to disabled to fix the problem.
>
> Here is my use case : I fill in a java class some information about a
> people, his hame and his age, and I want to check if he is an adult.
> Two different users have written a rule to check this. The first,
> living in
> place where a 18 years old people is an adult wrote this rule :
> ___________________________________________
> rule "Is Major"
>       when
>               $a : Applicant (age >= 18)
>       then
>               $a.setMajor( true );
>
> end
> ___________________________________________
>
> The second one, write this one :
> ___________________________________________
> rule "Is Minor"
>       when
>               $a : Applicant (age < 21)
>       then
>               $a.setMajor( false );
>
> end
> ___________________________________________
>
> I've tried to solve this knowledge base with a 19 years old people, but
> no
> conflict was detected.
> In fact the rules are executed sequentially and the result depends of
> the
> order the rules are called.
>
> My use case is very simple, but I think I am not considering it
> correctly.
> Or maybe it is impossible with forward chaining ?
>
> Does anyone can help me to solve this problem, by telling what is wrong
> or
> giving me some internet ressource link ?
>
> Thanks a lot in advance.
>
> --
> View this message in context: http://drools-java-rules-
> engine.46999.n3.nabble.com/Conflict-detection-problem-
> tp2664121p2664121.html
> Sent from the Drools - User mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users


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