Hi my fact object looks like this, class ProcessRequest { Long requestId; String processType; String assigneeUsers; List<String> businessData; //Getters and Setters } I have inserted the fact object into working memory in this way WorkingMemory workingMemory = ruleBase.newStatefulSession(); FactHandle factObject = workingMemory.insert(processRequest ); workingMemory.fireAllRules(); My question is how to use the values in the business data for comparison in the rules.drl file rule "Audit" when p: ProcessRequest(processType == "Audit" && SSN == 1234) then p.setAssigneeUsers("AuditUser1"); end When i try with the above rule it says no field extractor found for SSN, SSN is part of the businessdata(List<String>) Please do suggest me 1. How to make the Workingmemory aware of the Collection - businessData 2. Change the rules.drl file syntax to access values from Collection. -- View this message in context: http://www.nabble.com/Inserting-Collection-into-WorkingMemory-tp23975453p... Sent from the drools - dev mailing list archive at Nabble.com.