Data on the reliability and the failure modes of components and equipment used in industrial facilities is an important input to risk analysis, both for semi-quantitative methods such as LOPA and fully quantitative methods such as QRA/PRA. Depending on how this reliability data is collected, analysts can have more or less confidence that the data they use will be representative of the operation of equipment on their sites, and the safety assessment is valid.
Example questions: what is the failure frequency of a specific type of pump in my refinery? What are the pump’s failure modes (when it fails, how likely is it that we get some warning that failure is imminent; does it fail in a closed or open position)? What is the probability of failure on demand (PFD) of a specific safety device, such as a emergency shutoff valve?
Upon completion of this module, you should be able to describe various sources of reliability data, their use in the risk assessment process, and their relative advantages.
Operational Experience Feedback and reliability data
We recommend the following sources of further information on this topic:
Risø technical report Reliability Databases: State-of-the-Art and Perspectives
Booklet Failure frequency guidance: process equipment leak frequency data for use in QRA by DNV
Wired.com article Why Things Fail: From Tires to Helicopter Blades, Everything Breaks Eventually from 2010