If I remove /id equals to $id / in the WHEN part, I can set the id in the THEN part. But then the use case getOneObjectById does not work. -- View this message in context: http://drools.46999.n3.nabble.com/Drools-Guvnor-problem-tp3142574p3144190.html Sent from the Drools: User forum mailing list archive at Nabble.com.