AbstractThe failure mechanisms that can occur in a component in service are discussed. The mechanisms are categorized into three major classes: low-life failures, macroscopically non-localized damage accumulation, and macroscopically localized damage accumulation. The methods used to avoid these failure mechanisms are discussed in detail. The problem of fatigue life prediction is highlighted and the‘traditional’initiation life calculation method is compared and contrasted with fracture mechanics based methods. The importance of performing full scale component tests for highly stressed gas turbine parts is highlighted, both from the traditional lifing viewpoint and to validate fracture mechanics based calculations. Finally, some examples are given of the comparison of fracture mechanics fatigue life predictions with full scale component rig test results.MST/520