There’s a new paper in the Safety Instrumented System (SIS) section of PII’s Free Resources area, entitled SIL-3, SIL-2, and Unicorns (There Is a High Probability Your SIL 2 and SIL 3 SIFs Have No Better Performance Than SIL 1). This paper shows that specific human error during testing, calibration maintenance, and restoration of a SIF is a significant contribution to the true PFD of the SIF for SIL 2 and dominates SIL 3 designs. Unless the human errors are accounted for and then compensated for, it is more likely to find a Unicorn than to actually get two or three orders of risk reduction from SIL 2 and SIL 3 SIFs. Head over to the Free Resources section via the link below to download this important paper, and any of the other important free resource documents available to you from Process Improvement Institute!
http://www.process-improvement-institute.com/_downloads/SIL-3_SIL-2_and_Unicorns_GCPS-2019_FINAL.pdf
