(BMS), building automation system (BAS) or system control and data acquisition (SCADA) system) - capable of indicating any out-of- specification condition without delay e.g. by means of an alarm – Also helps with preventive maintenance and trend logging – Critical alarms easily identifiable, visible and/or audible • Fan interlock failure matrix • Fan failures can cause a system imbalance, resulting in a pressure cascade malfunction with a resultant airflow reversal.