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Practitioner 2 days

SIL Determination and Verification Workshop

Setting the target honestly, then proving the loop can meet it

Two distinct activities that get confused. Determination sets the required integrity from the risk. Verification proves a proposed loop achieves it. Delegates work through both, including the proof test coverage and common cause assumptions that most verification files leave unstated.

This course sits alongside our SIL Determination and Verification consulting work, so what is taught is what we do.

Who should attend

Instrumentation and process safety engineers performing SIL studies
Engineers reviewing vendor SIL verification reports
Maintenance planners setting proof test intervals
Project engineers accepting safety instrumented systems

Course content

Every module is taught with worked examples and exercises drawn from real plant, and adapted to your own process where the course runs in house.

1

SIL determination

  • Risk graph, risk matrix and LOPA approaches and the calibration behind each
  • Consistency between facilitators and how to test for it
  • Documenting the basis so the target can be defended later
2

The verification arithmetic

  • Average probability of failure on demand and risk reduction factor
  • The single channel result and the proof test interval as a linear multiplier
  • Dangerous detected and undetected failures, and diagnostic coverage
  • Summing sensor, logic solver and final element contributions
3

Assumptions that decide the answer

  • Proof test coverage and the failures a stroke test does not find
  • Mission time and what only gets cleared at overhaul
  • Common cause and the beta factor floor under redundancy
  • Why the final element usually dominates the loop
4

Architectural constraints

  • Hardware fault tolerance requirements and route 1H and 2H
  • Safe failure fraction and device type A against type B
  • Why favourable failure data cannot buy past a constraint
5

Calculation workshop

  • Delegates verify loops from their own plant or from provided data
  • Testing the sensitivity of the result to test interval and coverage
  • Peer review of each other's assumption sets

What you receive

  • A SIL verification calculation workbook
  • A determination calibration guide for your risk matrix
  • Worked verification examples including imperfect proof testing
  • Assessment result and attendance record

What changes afterwards

  • Targets are set consistently rather than varying by whoever facilitated
  • Verification reports state proof test coverage instead of assuming perfection
  • Proof test intervals in the report match what maintenance can actually deliver
  • Money goes to the final element where it changes the answer

Standards and references

We teach SIL Determination and Verification Workshop against IEC 61511 for determination and verification requirements and the codes listed with it, at the edition current when you run it.

IEC 61511 for determination and verification requirementsIEC 61508 part 6 for the simplified reliability equationsISA TR84.00.02 for SIL verification methodology

Run SIL Determination and Verification Workshop for your team

We will come back with dates, the pre-reading it needs and a cost per head. Tell us who is attending, what they already do day to day and whether you want it at your site or delivered online.

Ask about dates and cost