In your code, while constructing your RuleBase, you'll before compile your rules into KnowledgeRulePackage. This is done by using a KnowledgeBuilderFactory. It can be done at runtime, so whenever you change your java code inside .drl rules, you do not have to do a prebuilt of these rules (but you could, depends on what you want). If you compile your drl rules at runtime, you'll have to include the drools-compiler.jar within your libs. If you use precompiled rules package, you don't. On Fri, 10 Jul 2009 09:29:29 +0530, Pardeep.Ruhil(a)lntinfotech.com wrote: