Dynamic risk-based inspection methodology

Inspection methodologies have evolved in the past decades to explore optimal interval and inspection methods. The American Petroleum Institute has published several standards such as API-510, API 653, API 570 and API-580 to assist in determining inspection intervals based on equipment life, consequences of failure, degradation rate, and environmental impact. The most recent approach is the Risk Based Inspection, API-580 and API-581. The underlying assumption of this approach is that risk remains acceptable between two planned inspection or maintenance intervals. This condition may not hold true in a complex, fast-changing or degrading engineering system. This study presents an innovative method to assess risk for a dynamically changing system based on the system parameters that are continuously monitored. The calculated dynamic risk can be used to plan optimal inspection and maintenance intervals more efficiently. The proposed method is tested on several possible combinations of an engineering system. Efforts are also made to align and integrate the proposed method with API-581. This would help to implement a more accurate approach while maintaining the required industry standard to ensure safe operation with low uncertainty.