Condition that differs from what is expected or typical, or which differs from that predicted by a theoretical model.
Source: ISO 16530-1:2017, Petroleum and natural gas industries – Well integrity – Part 1: Life cycle governance, First Edition, March 2017. Global Standards
An in-service survey measurement that is outside the threshold considered acceptable from the design or most recent fitness-for-purpose assessment.
Source: API RP 2SIM, Structural Integrity Management of Fixed Offshore Structures, First Edition, November 2014. Global Standards