Invest in smoke detectors for every part of your facility; room or office.
Install dual sensor smoke alarms; make sure they contain both ionisation and photoelectric smoke sensors to detect small lingering fires and smoke.
Test your smoke detectors (and sprinkling system if installed) once a month.
Replace the batteries at least once a year (possible exception: non-replaceable 10-year lithium batteries; still, be sure to test them); many manufacturers also encourage a replacement of the smoke detectors after a decade.
Never disable a smoke alarm – they could save you lawsuits and more importantly, occupant lives.
Consider smoke alarms for the disabled.
Audible alarms (pauses between the siren wail allow for auditory communication) are available for the visually impaired; visual alarms (with a flashing light or vibrating pad) are available for the hearing impaired.