Proof Test Procedures

Proof Test Procedures required by IEC 61508 and IEC 61511

ESC is pleased to offer the development of new Proof Test Procedures, as required by IEC 61508 and IEC 61511, or the review and enhancement of existing procedures within companies.

If asked whether your Proof Test Procedures were “good, bad or ugly”, what would be your response?

  • Are your Proof Test Procedures legible to all parties, i.e. by both the author and the technician?
  • Have all the technicians been trained to the same standard for the systems being tested?
  • Are your Proof Test Procedures revisited and reviewed at regular intervals?
  • Are the failure modes needing to be tested fully covered by your Proof Test Procedures?
  • Can your proof test procedures demonstrate to the competent authorities that the full function and all failure modes are being tested? Are your Proof Test Procedures in line with HSE guidance?

ESC have specialist consultants who have vast experience in developing and improving Proof Testing Procedures for a number of industries, including: the oil and gas industry, the chemical industry and animal health.

In order to meet good practice as defined in IEC 61508 and IEC 61511, a PFD calculation for the SIF (as part of the SIL verification) is determined to show the integrity. The calculation is based on assumptions such as how often undetected dangerous failures are revealed by proof testing and the Proof Test Coverage (PTC), i.e. the frequency of proof tests and the ability in revealing any “hidden” faults.

It is important that the proof test for the safety functions can be repeated at every desired time period in a consistent and accurate manner. The Proof Test Procedure will allow for the proof test to be carried out at specified intervals by competent personnel while maintaining a consistent and accurate approach.

In aiding the client, ESC can help in implementing a formal competence assessment strategy (as detailed in Stage 4) and also offer a 1 Day Course on the Introduction to Safety Instrumented Systems for Technicians (IEC 61508/IEC 61511).

Further Information

Our Functional Safety FAQs are a great place to start if you have any questions.

If you’d like any further information or would like to talk to one of our consultants please Contact Us via our contact form and we’ll be glad to help.