I think normally setGlobal variables are only used when you want to be able to call back out to the java code again. (I'm not an expert by any stretch so please take that with a grain of salt.) So you might be able to just insert the list. I'm going to assume the List is really List<NombersUnTypeDefault> if that is not true please let me know. what about something like this? First is collects all the NombersUnTypeDefault that match your constraints from list then it counts them using an accumulate function. global java.util.List list rule "Calcul redondance" when $i: Number() from accumulate($c: NombersUnTypeDefault() from collect(NombersUnTypeDefault($code == "AAA", $int == 1) from list) , count($c)); then System.out.println($i); end -- View this message in context: http://drools.46999.n3.nabble.com/Drools-and-ArrayList-tp3140821p3144161.... 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