blinton wrote: Hi, you don't need to instantiate Java enum values. In fact, the java syntax simply does not support it, because the enum values specified in the enum declaration are the only allowed instances of the enum "class" generated by the compiler behind the scenes. How to use them with drools? Just insert one of the enum values into your working memory, like so: workingMemory.insert(Status.INCOMPLETE); This of course also works with variable "status" values, e. g.: private void insertStatus(Status actualStatus) { workingMemory.insert(actualStatus); } Best regards Ansgar