Worked examples
Seven functional safety problems with illustrative designs and data, computed with the First Out AI engine. Every input, result and chart is on the page, so you can rebuild each one in the app and check the numbers.
All worked examples
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Worked example First Out AI
A SIL 2 overpressure function that fails on proof test coverage
LOPA sets SIL 2; modelling the valve test that is really done drops the function to the SIL 1 band. Five fixes compared.
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Worked example First Out AI
A SIL 3 HIPPS where partial stroke testing closes the gap
Common cause failures of two identical valves set the floor. How often partial stroke testing must run to meet the required risk reduction.
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Worked example First Out AI
Fired heater fuel trip: choosing scanner voting for safety and uptime
1oo1, 1oo2, 2oo2 and 2oo3 flame scanners compared on PFDavg, fault tolerance and spurious trips.
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Worked example First Out AI
Tank overfill: when the environmental case sets the SIL
Two LOPA cases from one cause, and why meeting the SIL band is not the same as meeting the required risk reduction.
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Worked example First Out AI
Exothermic reactor: when common cause failures erase redundancy
A β sensitivity study shows the common cause factor deciding between SIL 2 and SIL 3.
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Worked example First Out AI
High demand mode: why PFDavg gives the wrong answer
A batch interlock demanded 2,000 times a year, verified as PFH, with the fault tolerance high demand requires.
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Worked example First Out AI
Extending the turnaround interval: which safety functions can wait
Ten functions recomputed at 1, 2 and 3-year intervals against their required risk reduction.