A method of exchanging a rules engine decision tree cache is disclosed. The method provides for provision accepting a command to build a replacement rules engine decision tree cache, replacing the existing cache if the decision tree creation process is successful, retaining the existing cache if the decision tree creation process is not successful, and providing specific error messages in the event that the replacement fails. The method allows an network operator to change the rules for the rule engine without disruption of real-time service and allows for a level of error checking prior to provisioning the new decision tree.