Quote Originally Posted by cosili View Post
Dear Najmi,
Fault tree analyses is the best method to obtain PFD and of course the SIL level.
Also there is a lot of dedicated tools for SIL evaluations..but also I NEED IT.
Regards,
Costin
Dear cosili,
I'm an HSE engineer in a gaz company, at this yime i'm doing a study on "SIL assessment of a detction gaz system". I had already do a database on this system and on its failures along three years up to now.
I'm calculating Its MTBF and Its MTTR but the question is : can λ be equal to 9 and more or is it an error on my job ? (this value is abtained on such gaz detector which commonly fail, half of time it's fail)
please can you help me to solve this problem
I used IEC 61508 & ISA 615XXXX (I dont remember the code exactly).