The Aerospace Industries Association (AIA) Rotor Integrity Sub-Committee (RISC) has proposed an enhanced damage tolerance design strategy for critical rotating parts intended to reduce the rate of uncontained rotor events. Building upon the industry committee’s experience in developing a probabilistic relative risk assessment methodology for hard alpha anomalies in titanium rotors, a similar probabilistic approach has been proposed for induced anomalies along machined hole surfaces in engine rotors. Key inputs to this strategy are the development of a surface anomaly distribution for machined holes and the benchmark of design target risk (DTR). The DTR is an FAA/industry agreed upon design target value of relative risk against which the results of the probabilistic risk assessment are compared.Copyright © 2006 by ASME