(52s) Business Case for PHA of Procedures (to find the accident scenarios that are otherwise missed)

Hazard evaluations, also called process hazard analysis (PHAs) have been performed formally in gradually improving fashion for more than five decades. Methods such as HAZOP and What-If analysis have been developed and honed during this time. Some weaknesses identified 30 years ago still exist in the majority of PHAs performed around the world. Critically, most PHAs do not thoroughly analyze the errors that can occur during startup, shutdown, and other non-routine (non-normal) modes of operations; sadly the commonly used approaches for PHA of continuous mode of operation only find about 5 - 10% of the accident scenarios that may occur during startup, shutdown, and online maintenance. This is true even though about 80% of major accidents occur during non-routine operations. Instead of focusing on the most hazardous modes of operation, most PHAs focus on normal operations (e.g., HAZOP of equipment nodes). In a majority (perhaps more than 80%) of both older operations and new plants/projects, the non-routine modes of operations are not analyzed at all. This means that perhaps 70% of the accident scenarios during non-routine operations are being missed by those PHAs. If the hazard evaluation does not find the scenarios that can likely occur during these non-routine operations, the organization will not know what safeguards are needed against these scenarios.

This presentation focuses on the business case for doing PHA of Procedures; the case is based on experience from thousands of PHAs. Data from PHAs/HAZOPs show that 50% to 85% of the risk reduction opportunities are found during PHA of procedures, resulting in 100,000,000 USD or more in risk reduction savings per large PHA/HAZOP. The return on investment for PHA of procedures (the savings in risk avoidance by implementing recommendation that are found during PHA of procedure) is more than 1000 times the cost of the PHA of procedures.