I've taken the rule on nabble (for strange reasons, it does not display correctly on mails ...). Wolfgang was right : rule "C020 - Gate charge (Out M)-B" salience 45 no-loop true when ChargeDetailEntity( opsDate_currentLeg >= "20110101 000000" ) and $charge : ChargeDetailEntity ( $tariffType : tariffType, $tariffCode : tariffCode, $chargeEtd : etd, billToCompany == "C020", chargeType == "YH", cntrStatus1 == "XM" ) and not( exists( $seq : ChargeDetailRefSeqEntity( $seqEtd : etd, (invSepCriteriaName == "C020 - Gate charge (Out M)") && ((adjType == $charge.adjType) && ((bargeJobId == $charge.bargeJobId) && ((billToCompany == $charge.billToCompany) && ((chargeType == $charge.chargeType) && ((consortiumCode == $charge.consortiumCode) && ((serviceCode == $charge.serviceCode) && ((vesselCode == $charge.vesselCode) && ((voyageCode == $charge.voyageCode) && (etd == $chargeEtd))))))))) ) ) ) then insert(createChargeDetailRefSeqEntity("C020 - Gate charge (Out M)", $charge, newSeqList)); retract($charge); end the first ChargeDetailEntity( opsDate_currentLeg >= "20110101 000000" ) is the problem. Don't know why there is 2 ChargeDetailEntity patterns, but I would put the contraint in the other ChargeDetailEntity pattern. This way, adding one ChargeDetailEntity object will only lead one rule activation. With the rule as this, the number of activiation you show in your log is normal ... PS : using a exists inside a not is redundant. not means "not exists" by itself. not( exists (X) ) is the same as not( X ) . ----- Mail original ----- De: "Wolfgang Laun" <wolfgang.laun(a)gmail.com&gt; À: "Rules Users List" <rules-users(a)lists.jboss.org&gt; Envoyé: Vendredi 18 Mai 2012 13:02:09 Objet: Re: [rules-users] Object activiates same rule many times Please show the rule. Exponentially growing activations can be caused by rules where the same fact type is used more than once. You'll have to use constraints inhibiting useless duplications, e.g., when $a1: A() $a2: A(this != $a1 ) then -W On 18/05/2012, Christina Lau <lau.christina(a)hit.com.hk&gt; wrote: Hi all, I find an odd pattern in the audit log. When an Object is inserted to the working memory, activation is created many times on same rule. The more objects are inserted, the duplicated activations are growing exponentially which degrade the performance a lot. Here attached part of the audit log: http://drools.46999.n3.nabble.com/file/n4000630/rule-DOCSEP-1337325521971... rule-DOCSEP-1337325521971.log In the log, - when object (130) is inserted, rule "C020 - Gate charge (Out M)-B" is activiated 129 times. - when object (131) is inserted, rule "C020 - Gate charge (Out M)-B" is activiated 130 times. Here is the rule of "C020 - Gate charge (Out M)-B", The "insert" in RHS only add ChargeDetailRefSeqEntity to working memory that I don't think it causes the recursive activation. And I'd already set no-loop to true. Does anyone offer some help here? Thank you very much, Christina -- View this message in context: http://drools.46999.n3.nabble.com/Object-activiates-same-rule-many-times-... Sent from the Drools: User forum mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users