Stale alarm

Stale alarm (also see Table IX/4.1.2-1) When an alarm goes in to alarm state but never return to normal state within 24 h time. This is similar to standing alarm. Shelved alarm is an alarm resulted on account of alarm suppression technique/ mechanism initiated by operator to temporarily suppress a set of alarms until an underlying problem can be corrected. Shelved alarms must be presented to the operator. (Such shelving should be done with due authorization for with detailed reasoning noted and displayed. A review of the same after change of shift should be undertaken). When equipment is under maintenance alarms associated with it may be shelved. 

Stale alarm (see Clause <5% on any day action plans to address ... 

Alarm overload More alarm than manageable Alarm floods Nuisance alarms Chattering alarms Standing/stale alarms Redundant alarms Alarms which have no response Alarms with the wrong priority... 

Auditable Testing, classification, and prioritization of alarm and performance measurements are major issues related to this point. Each alarm is checked against its becoming stale, standing shelved, etc. needs to be considered. 

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