Assessment of relevant indicators of non-destructive testing

The development of industrial production has stimulated the formulation of new safety requirements for industrial facilities and, consequently, new reliability characteristics, which are determined, among other things, using non-destructive testing (NDT) methods and tools. However, simple detection of discontinuities (defects and damage) and traditional assessment of their acceptability in accordance with established rejection standards no longer meet modern requirements for operational safety and equipment reliability. The purpose of this work is to evaluate the informativeness of NDT indicators to ensure specified criteria for reliability and operational safety. Key parameters used for evaluating discontinuities — such as size, location, shape, orientation, and relative positioning — allow for calculating the structural integrity of an object and predicting its safe service life within the framework of fracture mechanics. The paper examines approaches and requirements for NDT driven by the need to ensure the reliability and informativeness of the results obtained. The importance of using probabilistic characteristics of NDT systems is demonstrated, including Probability of Detection (POD) curves and ROC analysis, which integrates data on detection and false alarm probabilities. A classification of NDT systems by quality levels based on probability of detection and false alarm values is proposed. The results obtained can be used to improve NDT methodologies, incorporating an optimal combination of methods and probabilistic characteristics of detection and false alarms, to facilitate more informed decision-making regarding the necessity of repair or continued operation of components with discontinuities.