I was looking for advice regarding the frequencies for ITM of water based sprinkler systems. These are located in public schools. I've had conflicting reports regarding quarterly testing of systems, primarily alarms. I saw there was a study in 2012 regarding "applying reliability Based Decision making to ITM, and wondered if there has been any leeway provided on the testing frequency based on the reliability/failure rates for such systems. Mechanical alarms have the most frequent testing requirement at Quarterly. If there are no mechanical alarms, is semi annual permitted? Is there evidence through failure rates supporting the frequency of testing? I realize there is also maintenance and Inspection which are different aspects of a system. I've always consulted NFPA 25, should I be looking at another standard for alarms and other components?