The PDS method is used to quantify the safety unavailability and loss of production for safety instrumented systems (SIS). The method accounts for all relevant failure categories; technical, software, human, etc. The PDS method is documented through a PDS method handbook and a PDS data handbook (latest issued in 2010).
The PDS method handbook present simple caculation formulas for calculating Probability of Failure on Demand (PFD), and provides unavalability formulas for continuously (high demand mode) operating systems. The PDS method is in line with the main principles advocated in the IEC 61508 / 61511 standards, and is a very useful tool when implementing and verifying quantitative Safety Integrity Level (SIL) requirements as described in these standards.
The PDS data handbook comprises recommended failure data on various SIS components, both topside and subsea. The handbook is based on extensive experience with operation of SIS in the Norwegian petroleum industri, and presents data applicable for performing SIL analyses according to IEC 61508 / 61511.
Purchase PDS handbooks.
Published February 6, 2012
