© 2015 - 2019 Process Safety Integrity

Reducing RISK, Protecting PEOPLE, PLANET, PLANT, PRODUCTION, PRODUCT & PROFILE

January 6, 2019

September 3, 2018

March 26, 2018

Please reload

Recent Posts

Why worry about something that isn't going to happen

June 10, 2019

1/1
Please reload

Featured Posts

LOPA Sensitivity

May 23, 2015

 

Has anyone conducted LOPA analysis with Upper & Lower values on the Frequency & Probability values ?

 

We all know that the best data is site specific, however it's not always available and therefore we often use published sources such as Exida SERH, SINTEF OREDA, CCPS PERD etc.

 

Not knowing exactly how comparable our 'actual' data is or will be against the generic values; applying upper & lower "confidence" values provides an overall range of outcomes around a medium (generic published) basis.

 

Obviously as you multiply up the probabilities, the range gets bigger (ref attached example image) which gives the designer a challenge in determining which frequency result to compare to the risk tolerability criteria.

 

I've seen this approach applied to SIL Verification calculations to provide a range of possible PFDavg, but not aware of it being used for SIL Determination (LOPA).

 

All thoughts welcome - thanks

Share on Facebook
Share on Twitter
Please reload

Follow Us