Risk-Based Inspection (RBI) is an optimal maintenance business process used to examine equipment such as pressure vessels, heat exchangers, and piping in industrial plants. RBI is a decision-making methodology for optimizing inspection plans. The RBI concept lies in that the risk of failure can be assessed to an acceptable level, and inspection and repair are used to ensure that the level of risk is below that acceptance limit. It examines the Health, Safety, and Environment (HSE) and business risk of ‘active’ and ‘potential’ Damage Mechanisms (DMs) to assess and rank failure probability and consequence. This ranking is used to optimize inspection intervals based on site-acceptable risk levels and operating limits while mitigating risks as appropriate. RBI analysis can be qualitative, quantitative, or semi-quantitative.
Probability of Failure (PoF) is estimated based on the types of degradation mechanisms operating in the component. It is calculated as the area of overlap between the distributions of the degradation rate for each degradation mechanism (based on uncertainties in rate) with the distribution of the resistance of the component to fail.
Consequence of Failure (CoF) is defined for all consequences that are of importance, such as safety, economy, and environment. Consequence of failure is evaluated as the outcome of a failure based on the assumption that such a failure will occur.
Accuracy is a function of analysis methodology, data quality, and consistency of execution. Precision is a function of the selected metrics and computational methods. Risk presented as a single numeric value (as in quantitative analysis) does not guarantee greater accuracy compared to a risk matrix (as in a qualitative analysis), because of uncertainty that is inherent with probabilities and consequences.
RBI is most often used in engineering industries and is predominant in the oil and gas industry. Assessed risk levels are used to develop a prioritized inspection plan. It is related to (or sometimes a part of) Risk-Based Asset Management (RBAM), Risk-Based Integrity Management (RBIM), and Risk-Based Management (RBM). Generally, RBI is part of Risk and Reliability Management (RRM). The basis of most RBI programs is the Corrosion Circuit, in which each circuit can be compared for relative risk levels to aid in inspection and maintenance planning.
Risk-Based Inspection (RBI) is an analysis methodology and process that, as opposed to condition-based inspection, requires qualitative or quantitative assessment of the probability of failure (PoF) and the consequence of failure (CoF) associated with each equipment item, piping circuits included, in a particular …
Risk-based inspection (RBI) is an asset integrity management methodology used to prioritize assets for inspection based on associated risks. By focusing inspections on priority assets, RBI maximizes resources by concentrating them on equipment with higher risks while avoiding assets with inconsequential risk.