Which of the following is not a defined scope of the NFPA 72?

The correct choice highlights an area that is outside the defined scope of NFPA 72. This standard primarily focuses on the requirements for fire alarm systems, their installation, testing, inspection, and maintenance, as well as provisions to ensure their proper functioning in a fire emergency.

While NFPA 72 does address aspects of fire alarm systems, such as the technical specifications for how they should operate and be maintained, it does not stipulate specific instances or conditions under which a fire alarm system must be implemented in a building. The determination of when a fire alarm system is required typically falls under local building codes and fire safety regulations. These codes are influenced by various factors such as building occupancy types, size, and life safety considerations, which NFPA 72 does not cover in depth.

Other elements within NFPA 72, such as testing standards and personnel training guidelines, are indeed components of its scope, establishing best practices for ensuring fire alarm systems are effective and that personnel are prepared to maintain and operate these systems correctly. Therefore, it is clear that the requirement for when a fire alarm system should be installed is not a focus area of NFPA 72.