Hi, Sorry, the Problem statement did not come with the attchment. The problem is: I am serializing working memory(WM). But after deserializing that, if I try to modify the corresponding RuleBase that is not getting reflected. I mean, after loading the serialized WM even I add a package to the corresponding RuleBase, new Rules are not getting fired for newly added facts. Or I remove a package from the corresponding RuleBase, even removed Rules are getting fired for newly added facts. So, Once WM is deserialized any chage to the corresponding RuleBase is failing. I have attached the test program & test rules. Thanks Siddhartha