Hi, I want to replace an outdated function defined in a drl file without touching that file, is this possible? (in 5.5.0) The java application part that loads the resources cannot be touched as well. It is configured to read all the drl files from a predefined folder, I am only allowed to add-in new drl files. Here are what I have tried: 1. Create a new drl file with the new function with same package name and same function name This works *only* if the new file is loaded after the old file. As I cannot change how the java application loads the resources, I cannot guarantee the new file is always loaded after the old one, so I tried the next method. 2. Create a new drl file with the new function with same function name. Add a rule with high salience and call drools.getKnowledgeRuntime().getKnowledgeBase().removeFunction("old_package", "oldFunc"); Function newFunc = ((org.drools.impl.KnowledgeBaseImpl)drools.getKnowledgeRuntime().getKnowledgeBase()).getRuleBase().getPackage("new_package").getFunctions().get("oldFunc"); // a new implementation with the same name ((org.drools.impl.KnowledgeBaseImpl)drools.getKnowledgeRuntime().getKnowledgeBase()).getRuleBase().getPackage("old_package").addFunction(newFunc); But this didn't work. When the rules are fired, it complains about the old_package cannot find the function anymore. Could anyone from the Drools team provide some help on this? Thanks a lot! -- View this message in context: http://drools.46999.n3.nabble.com/Replacing-an-old-function-in-drl-tp4024... Sent from the Drools: User forum mailing list archive at Nabble.com.