ESC present at IChemE’s Hazards27

ESC presnet at IChemE Hazards27ESC’s Ron Bell OBE and David Green will be presenting on Proof Testing “Proof Testing… A key performance indicator for designers and end users of Safety Instrumented Systems” at Hazards on Friday 12th May.

Hazards is held annually in the UK and next takes place on 10th to 12th May 2017 at the International Convention Centre (ICC) in Birmingham.

Aimed at anyone who is active in process safety and risk management, Hazards provides essential technical insight into how to improve process safety performance, and reduce the risk of  hazardous events, as well as excellent networking opportunities.

Proof Testing… A key performance indicator for designers and end users of Safety Instrumented Systems

Proof Testing is a key performance indicator with respect to the achievement of functional safety and the paper sets out a structured approach to the development of Proof Test Procedures for Safety Instrumented Functions (SIFs) within the process sector and guides the reader through a five stage process to ensure the development of robust Proof Test Procedures. This requires addressing both the technical requirements and the competence requirements of those having responsibilities for Proof Testing.

This staged approach has been established based on two decades of operational experience by the principal author, within top tier COMAH establishments within the UK, and subsequent consultancy work within multiple industry sectors.

The five stage process consists of:

  • Stage 1: Specification of the Proof Test Procedures;
  • Stage 2: Verification of the proposed Proof Test Procedures;
  • Stage 3: Modification to the Proposed Proof Test Procedures;
  • Stage 4: Competence of those managing and undertaking the Proof Test Procedures;
  • Stage 5: Review of the Proof Test Procedures to assess the their effectiveness.

Current good practice in the process sector, with respect to functional safety, is to achieve compliance with IEC 61511 [1] and IEC 61508 [2]. The approach adopted by HSE is to benchmark the functional safety achieved, including Proof Testing, against requirements in IEC 61511 [1] and IEC 61508 [2].

The presentation covers the operational challenges to optimise Proof Testing with minimum business interruption. In the context of dangerous random hardware failures, the presentation will cover:

  • Imperfect Proof Testing versus Perfect Proof Testing and optimisation of overhaul periods
  • Modification of Proof Tests with underpinning justification and the implications of inappropriate modifications
  • The impact on facility resources when an overly conservative approach is taken to the Proof Test interval

Please head to the IChemE website to see the full program and to register.

IChemE Hazards27


[1] IEC 61511-1, Functional safety – Safety instrumented systems for the process industry sector. Edition 2, 2016, Corrigendum edition.
[2] IEC 61508, Functional Safety of Electrical/ Electronic/ Programmable Electronic Safety Related Systems. Edition 2, 2010.