Alarm management is an ongoing activity, and sometimes the most difficult part is getting off to the right start. According to ISA-18.2, the best place to start is with an alarm system performance benchmark and audit. This can serve as the starting point (or baseline) for your performance improvement program, or as an interim snapshot.
A good performance benchmark establishes how alarm system performance compares to the recommended metrics defined in ISA-18.2 / IEC 62682. It also identifies systematic design issues that should be corrected (typically by publishing guidelines in an alarm philosophy document and by performing alarm rationalization).
If you are “taking credit” for alarms in a PHA or LOPA, then a performance assessment will help you determine whether the alarm safeguard / layer of protection is likely to be effective in reducing process safety risk.
|Metric||Target Value||As Found System Totals||Performance|
|Percentage contribution of the top 10 most frequent alarms to the overall alarm load||~< 1% to 5% max with action plans to address deficiencies||69.8%||Concern|
|Quantity of chattering and fleeting alarms||ZERO, action plans to correct any that occur||92||Concern|
|Stale alarms||< 5 present on any day, with action plans to address||24||Concern|
Figure. Gap Assessment: Nuisance Alarms
Figure. “Bad Actor” list – Top Ten Most Frequently Occurring Alarms
SyTech and exida have partnered to provide you an alarm system performance assessment that documents actual performance against recommended targets, identifies gaps, and provides recommendations on how to address the gaps, as well as creating an alarm management program.