Functional Safety Across Industries Practice Test

A repair-time assumption for a 1oo1 shutdown valve is 24 hours after detected dangerous faults. The site has no spare parts, purchasing takes six weeks, and wet instrument air makes failures more likely during winter. What is the best lifecycle decision? The evidence package also includes an assessment action list with one item still open.

A hydrogen blending skid retires an old tank overfill SIF after adding a new independent protection layer. The old proof-test work orders remain active, while the new credited function has no proof-test task or failure-data collection. Which lifecycle risk is most serious? The evidence package also includes a shift log note from an abnormal startup.

A technical safety concept for an lane centering feature states "enter degraded mode" on sensor disagreement. In high ambient temperature, degraded mode surprises the driver and increases steering effort abruptly. What is missing from the safety case? The evidence package also includes a vendor safety manual excerpt with assumptions of use highlighted.

A LOPA for a flammable vapor release credits an alarm and a SIF that both use the same transmitter on the polymerization kettle. The team argues the alarm is independent because the operator display and safety logic are separate. What should be done? The evidence package also includes a vendor safety manual excerpt with assumptions of use highlighted.

A team assigns SIL 3 to every SIF on a fired heater because "higher SIL is safer." Some functions protect equipment only, one addresses a credible fatality, and another prevents a minor environmental release already covered by a dike. What is the best objection? The evidence package also includes a shift log note from an abnormal startup.