What method is commonly used for estimating event frequency in LOPA?

The correct method for estimating event frequency in Layer of Protection Analysis (LOPA) is the use of historical data analysis. This approach involves examining past incidents, near misses, and relevant operational data to determine how often specific hazardous events have occurred in similar contexts. By analyzing this historical data, one can establish a realistic frequency of events, which is essential for accurately assessing risk and determining the necessary protective layers.

Historical data provides a foundation for understanding the likelihood of incidents based on empirical evidence rather than assumptions or theoretical probabilities. This makes it a reliable method for informing risk assessments and enhancing the robustness of safety systems.

Other methods, while potentially useful for different purposes, do not provide the same level of reliability in estimating event frequency for LOPA. Theoretical simulations, while they can model potential scenarios, may not accurately reflect real-world conditions. Financial risk assessments focus on economic impacts, which are not directly linked to estimating the frequency of hazardous events. Safety audits typically evaluate the effectiveness of safety systems and procedures rather than calculating event frequencies. Thus, historical data analysis stands out as the most effective method for this purpose in the context of LOPA.