Although the commercial engine disk failure rate continues to decrease, the FAA and the Engine Industry have found it necessary to make further enhancements to the traditional approach to determining disk service lives. This presentation will provide an overview of the essential elements involved in the traditional approach as well as the improved methodology. While the traditional approach has served the flying public well, a more comprehensive approach has evolved which accounts for the potential existence of anomalies. The improved techniques are based on the recognition that anomalies may not be detectable by existing nondestructive inspection techniques and can reduce the life of components by acting as crack initiation sites. There are two categories of potential anomalies: Inherent anomalies can occur during the melt processes, while Induced anomalies are produced during machining, maintenance and operation. Methods have been developed to address Titanium melt related anomalies during the design phase and the framework for this approach is outlined in an FAA Advisory Circular 33.14-1, “Damage Tolerance for High Energy Turbine Engine Rotors.” However further efforts are required by the FAA, the engine manufacturers and the alloy producers to deal with other disk materials as well as manufacturing and service induced anomalies.