Risk Based Inspection (RBI) is a risk based approach to prioritizing and planning inspection used in engineering industries, and predominant in the oil and gas industries. This type of inspection planning analyses the probability (or likelihood) and consequence of failure of an asset to calculate its risk of failure. The level of risk is used to develop a prioritised inspection plan for the asset. It is related to (or sometimes a part of) Risk Based Asset Management (RBAM), Risk Based Integrity Management (RBIM) and Risk Based Management (RBM). It is used to prioritise inspection, usually by means of non-destructive testing (NDT), requirements for major oil platforms, refineries and chemical installations around the world. The resulting inspection plan outlines the type and frequency of inspection for the asset. It is used for industrial pipework, process systems, pipelines, structures and many other types of assets in these industries. Items with high probability and high consequence (i.e. high risk) are given a higher priority for inspection than items that are high probability but for which failure has low consequences. This strategy allows for a rational investment of inspection resources.

Risk Based Inspection (RBI) is a proven method used to optimize inspection activities based on risk analysis. RBI improves plant reliability and safety whilst reducing unplanned outages and repair costs. Once the RBI program is operational inspection learning is fed back to help lower the risk profile of an asset’s equipment.

The purposes of RBI include:

• To move away from time based inspection often governed by minimum compliance with rules, regulations and standards for inspection.
• To apply a strategy of doing what is needed for safeguarding integrity and improving reliability and availability of the asset by planning and executing those inspections that are needed.
• To provide economic benefits such as fewer inspections, fewer or shorter shutdowns and longer run length.
• To safeguard integrity.
• To reduce the risk of failure.
• To Increase plant availability and reduce unplanned outages.
• To Reduce inspection and maintenance costs without compromising safety or reliability.
• To provide a flexible technique able to continuously improve and adopt to changing risk environment.
• To ensure Inspection techniques and methods are clearly defined based on thorough understanding of potential failure modes

There are many international engineering standards and recommended practices that outline requirements, methodologies and the implementation of RBI. Included in these are API RP 580 & 581.

From Wikipedia