PSI - Issue 70

Rajesh Dube et al. / Procedia Structural Integrity 70 (2025) 365–371

366

When properly implemented, the Risk based Work Selection (RBWS) helps asset owners and operators to identify, prioritize and optimize maintenance activities taking into consideration the Safety, Health, Environmental and Economic consequences. RBWS utilizes the risk matrix (American Petroleum Institute [API], 2025) to look at the risk in terms of the probability and consequences of failure. If systematically applied by maintenance, operations, and technical staff, RBWS is a powerful tool to minimize unnecessary work, repair scope and downtime (Anderson, n.d.). However, it has always been a challenge for an integrity engineer to select an appropriate RBWS approach to decide the risk and mitigation plan for a structural anomaly. Figure 1.0 shows the RBWS typical work sequence.

Fig. 1 RBWS work sequence

Nomenclature AI

Artificial Intelligence

ALARP

As Low as Reasonably Practical Consequence of Failure Close Visual Inspection General Visual Inspection Probability of Failure Risk Based Inspection Risk Based Work Selection

COF CVI GVI POF RBI

RBWS

2. Methodology adopted for RBWS RBWS can be accomplished by following one or a suitable combination of multiple approaches that exists. Based on author’s experience and knowledge , two approaches; final failure & progressive failure of structural components are very practical and effective in accomplishing RBWS goals. The first step in determining the final risk, for both the approaches, is identifying the correct damage mechanism and associated failure mode (API, 2025). The next step is to develop credible scenario for the identified damage mechanism. Once credible scenario is established, a further step is to determine the probability of occurrence of credible scenario, consequence is then factored into the probability to determine the final risk. The following sections discuss in detail the methodology and applicability of each of these two approaches. Figure 2 below shows structural component typical corrosion damage mechanism, associated failure mode and its utilization in the final failure and progressive failure approaches.