PDS Data Handbook: Reliability Data for Safety Equipment

The “PDS Data Handbook” is the ideal companion when doing reliability analysis of Safety Instrumented Systems (SIS). The reliability data in the handbook are well suited for SIL analyses according to IEC 61508 and IEC 61511 standards.

The handbook provides reliability data based on field feedback for components of safety instrumented systems, subsea and drilling equipment and selected non-instrumented safety critical equipment. Considerable effort has been made to ensure that the data are credible, traceable, documented and justified, in line with requirements in the IEC 61508 and IEC 61511 standards.

Compared to the 2013 edition of the handbook, the main changes are:

  • Greatly expanded data basis, including comprehensive and more recent operational experience
  • New equipment groups are added
  • For several sensors and final elements, the failure rates differentiate between relevant attributes such as dimension, measuring principle, process service, etc.
  • Updated values for the common cause factor (β factor), diagnostic coverage (DC) and random hardware fraction (RHF)
  • Improved data traceability and a more datailed assessment of data uncertainty

An electronic version (in PDF-format) of selected pages from the «PDS Data Handbook» can be viewed here.

PDS Method Handbook: Reliability Prediction Method for Safety Instrumented Systems

PDS method handbook

The “PDS Method Handbook” gives a description of the PDS method, including the mathematical details. It has also been the objective to make it comprehensible to the non-expert.

The IEC-standards 61508 (”Functional safety of safety-related systems”) and IEC 61511 (Functional safety — Safety instrumented systems for the process industry sector) provide useful information and guidance on safety requirements regarding the use of Safety Instrumented Systems (SIS). In the latest «PDS Method Handbook» the notation has been further updated in order to be in line with the IEC standard. The objective has been to “keep the best of the PDS method and at the same time to adapt the method to terms and requirements in IEC”.

New features of this 2013 Edition of the PDS Method Handbook include:

  • Calculations for multiple safety systems
  • Updated model for common cause calculations
  • Thorough discussion of different demand mode situations
  • How to incorporate the effect from reduced proof test coverage (PTC)

An electronic version (in PDF-format) of the first three chapters of the PDS Method Handbook (2010 Edition) can be viewed here.