Commercial and large-scale residential buildings that have fire alarm systems are well-protected from most severe fire damage as long as the alarm system continues to work as it should. Like other mechanical and computerized systems, though, an alarm system can deteriorate over time. Because the system usually lies dormant (or it appears to be dormant to those in the building every day), it can be difficult to determine if the system is nearing the end of its lifespan. Three considerations need to be looked at repeatedly when evaluating the condition of the system.
One is simply the age of the system, and for two reasons. Older systems won't have the technological advancements that newer systems have. This doesn't matter so much for systems that are only a few years old. However, systems that are several years, going on decades, old need to be replaced. The other factor regarding age is that the controls can deteriorate from environmental exposure, pest exposure (such as rats chewing through wires inside walls), and gathering dust in areas not easily accessible during inspections.
All alarm systems need to be inspected yearly. While this will not expose all problems, such as the aforementioned pest chewing in walls, it will let you see what is happening with much of the system and whether there is a burgeoning delay or other problem in sounding the alarm. If each inspection turns up more and more problems, it is time to replace the system. A working system should not require a lot of repair or adjustments each year.
Laws regarding alarm systems can change yearly. While many systems are grandfathered in when new changes take effect, you can't count on this. Plus, should something like a devastating fire occur, the age and code-readiness of the system will come into question even if it has been grandfathered into the new code. If there have been substantial changes to laws about alarms in the past few years, it is time to at least bring the current system up to code if not replace it entirely.
If you have an alarm monitoring company working with you, you can see what its recrods show regarding false alarms, too. These may indicate a problem with the system and give you further reasons to change the controls or other parts. It would be a good idea to meet with the monitoring company, like Fyr Fyter Inc, and see what other systems it handles and whether those have more stable records.