Frequently Asked Questions
I have a question regarding the correct way to simulate voting logic. I don’t understand how different PFD values are calculated if the same voting logic (e.g. 2oo3) are considered within different channels or one single channel.
Last Updated a year ago
The difference you see in the calculation results is due to the different level of detail in the models that you are using in the two calculations. The 2oo3 model that you use when modeling the SIF all in 1 group is very detailed as it accounts for intermediate states. The 2oo3 model that you use when modeling the SIF using 3 groups combines the individual group probability of failures in the SIF probability of failure. Repair actions that occur within the group are not covered at the higher voting between groups levels.