This document deals with the reliability of application of inspection procedures. A method to ensure that the inspection of defects thanks to fracture mechanics is reliable is described. The Systematic Human Error Reduction and Prediction Analysis (SHERPA) methodology is applied to every task performed by the inspector to estimate the possibility of error. It appears that it is essential that inspection procedures should be sufficiently rigorous to avoid substantial errors, and that the selection procedures and the training period for inspectors should be optimised. (TEC). 3 refs.