ISA Group on LInkedin — This APP by Pierluigi Meloni, Controls Engineering Manager at GE Oil & Gas, allows the SIL (PFD and RRF) calculation of a SIF modelled as input+logic solver+output.
It also calculates the MTTFs as per ISA-84 [Electrical/Electronic/Programmable Electronic Systems (E/E/PES) for Use in Process Industry Safety Applications] formulae.
The inputs for the calculations are the failure rates in FIT (the app provides a converter from flr/hrs) and a simple wizard to calculate Lambdas from PFD, Proof test interval and MTTF.
Additionally, it calculates, given the HFT and the SFF, the architectural constraints supporting both IEC-61508 and IEC-61511 tables. Continue reading