ABSTRACT
This chapter describes basic concepts associated with the decision theory and the fundamental concepts of sizing and detection. It presents the most widespread concepts: Probability of Good Assessment and Probability of Indication. The chapter examines the sources of uncertainties, epistemic and aleatory, involved in a condition assessment by inspection. A wide range of Non Destructive Testing (NDT) equipments have been tested using rigorous test procedures to ensure reliability and reproducibility of measurements. Almost all NDT tools provide data on specific locations and marginal distributions are thus obtained. Maintenance of existing aging infrastructures is generally based on condition assessment. To achieve certain goals, the condition assessment may be considered effective when the aging model parameters are updated using Bayesian techniques for instance. The chapter explores a wide range of illustrations and case studies which covered the fields of pitting and uniform corrosion, crack, and voids assessment.
