In one embodiment, a method implemented by a processor that receives plural sets of values corresponding to plural matched pairs of anomalies from a first inspection and second inspection following the first inspection, a first portion of each pair corresponding to the first inspection and a second portion of each pair corresponding to the second inspection, the plural sets of values corresponding to wall loss information for plural locations of a fluid carrying vessel; computes first and second statistical descriptions of a respective accuracy of the first and second inspections; and computes a revised estimate of the plural sets of values based on the first and second statistical descriptions.