Guvnor (as well as Drools in general) allows for defining packages which import facts from different java packages with the same name. In a technical rules file, this problem can be resolved obviously by fully qualifying the names of the facts used in the rule(s). In the business rule editor however the user is presented with two names in the facts drop down and can only pull properties from the last type added in the imports. The editor should have some capability to sort this out either by appending a package name where collisions occur or by appending a (1), (2),..., suffix to the names of the classes and internally mapping the facts back to their respective classes. The error in the logs when validating a resultant rule using the editor gives the error:

Unable to find unambiguously defined class...