How PFD Value has been calculated in Table 2 of 3BSE034876-510 Rev A Reliability and Availability manual?
Can any one please share exact formulas used to calculate PFD Value shows in "Table 2. AC 800M HI Safety reliability data" of Document No. 3BSE034876-510 Rev A i.e. "AC 800M High Integrity Reliability and Availability" manual?
Appreciate if any one can also share one example showing PFD Value achieve as stated.
As per my best knowledge,
PFD = Lamda(DU) x T is used.
Where, T is 20 years i.e. 175200 hours (Ref. : AC 800M High Integrity Safety Manual 3BNP004865-514 Page No. 154)
For I/O DI880, where Lamda(DU) is 3.52E-11 and T is 175200 hours.
PFD = Lamda(DU) x T
PFD = 3.52E-11 x 175200
PFD = 6.16E-6, which is matching to Table 2 PFD Value.
Here 2oo2 voting simplified PFD Formulas is used. (Ref. : ISA-TR84.00.02-2002 - Part 2)
Can any one please confirm whether my understading is correct or not?
Source: ISA-TR84.00.02-2002 - Part 2