What are the key principles of alarm management in SCADA/HMI systems?

Alarm management principles (ISA-18.2): alarms should be actionable (require operator response), each alarm needs defined response procedure, avoid nuisance alarms (flooding, chattering), prioritize by consequence (high/medium/low), provide clear alarm messages indicating problem and action. Key metrics: alarm rate (target <10 per hour), standing alarms (target <10), and alarm flood prevention. Implement alarm shelving for known conditions, and conduct regular alarm rationalization. Poor alarm management leads to operator overload and missed critical alarms.