Hello Drools Experts, I have a question on activation group and trying to understand the mechanism. I have the following rules in a .drl file : import function com.test.utils.StringUtil.isEmpty; import function com.test.utils.Logger.log; rule "r1" salience 10 activation-group "fireOnlyOnce" when SomeObject($s: someStringKey) eval(isEmpty($s) // static java method imported as function then log("doSomething"); end rule "r2" activation-group "fireOnlyOnce" when SomeObject($s: someStringKey) eval(checkWithDB($s) // Make a call to the DB to validate someStringKeyis valid then log("doSomething"); end In "r1" I am checking for 'someStringKey' is not null or empty. In "r2" , I am making a call to the DB to check 'someStringKey' is a valid id. During the debug, I found out that both "r1" and "r2" is fired but only one consequence is executed depending on the outcome of the r1. I want "r2" to fire only when "r1" evaluates to false. How can I achieve this in Drools? Thanks for your time and appreciate your help. -- View this message in context: http://drools.46999.n3.nabble.com/Drools-Activation-Group-tp3546607p35466... Sent from the Drools: User forum mailing list archive at Nabble.com.