Efficacy

Efficacy is defined in the National Construction Code (NCC) to define the degree to which a system achieves a design objective given that it performs to a level consistent with the system specification during the relevant fire scenario.

Automatic warning for occupants (H3P2)1
In a Class 1 building, occupants must be provided with automatic warning on the detection of smoke with an efficacy greater than 0.95 and a reliability greater than 0.95, so that they may evacuate in the event of a fire to a place of safety appropriate to the—

1. function and use of the building;and 
2. occupant characteristics; and
3. fire load and combustion characteristics; and
4. potential fire intensity; and
5. fire hazard.

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  NCC 2022 Volume Two - Building Code of Australia