RBI 581 Overview

API RBI 581 is an approach to qualify and quantify risks. It involves detailed calculation methods to determine an inspection plan. The output of the API 581 RBI assessment is the same as the S-RBI output: the inspection frequencies or intervals; the scope of work; and priorities.

Take Note

• We are in the process of implementing API 581 in IMS.

• The Consequence of Failure (CoF) calculation has already been implemented.

• Currently we are implementing the Probability of Failure (PoF) calculations for each API 581 Damage Factor (DF).

• All DFs will be third-party verified.

• Delivery is expected beginning of 2025.

Risk = Probability x Consequence

Risk = PoF x CoF

Risk = [gff*Df(t)*FMS] x CoF

The implemented Consequence of Failure (CoF) calculation applies to all Damage Factors. Relevant calculation tables can be viewed in the IMS settings.

The Probability of Failure (PoF) is computed from: gff * Df (t) * FMS where gff is generic failure frequency, Df(t) is Damage Factor, and FMS is Management Systems Factor. The FMS can be defined on Site/Plant/Unit level in Settings.

Either a balanced or unbalanced API RBI matrix can be selected (on Site level) and three Criticality Targets can be set: Risk Target Criteria (set on Site/Plant/Unit level), PoF Target (set in RBI assessment), or Legal/Local Inspection Interval (LII) target (set in RBI assessment). Through iterative analysis of the Age, a Maximum Inspection Interval (MII) is determined. This is the number of years required for Risk to reach the Next Inspection Date (NID).