
Read the post to learn about
the top nine indicators of poorly designed alarm system and ineffective alarm management, and identify the ones that are present in your facility.
1) Lack of clarity on alarm definition
and prioritization: When alarm criteria are not clearly
defined, it can result in situations where some alarms do not require a
response from the operator - alarms with no defined purpose. The alarm system
in such cases has too many informational and low-priority alarms, which increases
the noise and confusion in the control room.
2) Alarm floods:
If during abnormal situations or a plant upset, operators get flooded with a
large number of alarms (10 or more alarms in any 10-minute period per operator)
then there is some problem in your alarm system design.
3) High number of alarms during normal
operations: If your operators are overwhelmed with alarms
even during steady state operating conditions, it is a clear sign that your alarm system needs some serious fine tuning.
4) Nuisance and repetitive alarms:
These alarms appear frequently throughout normal system operation and can reduce
an operator's confidence in the alarm system. These alarms mask the important
alarms, ones that require operator attention and response.
5) Consequential or Cascading alarms:
These are alarms that tend to be raised consistently as a consequence of some
other alarm, they always occur together. A large number of consequential alarms
can cause an alarm flood, which can overwhelm operators and subsequently render
the alarm system ineffective.
6) Unclear alarm messages:
Unclear alarm messages do not provide meaningful information to the operator
concerning the cause of the problem or the corrective action. The lack of
proper guidelines for alarm implementation affects an operator’s ability to
effectively respond to alarms.
7) High number of high-priority alarms:
Presence of too many high-priority alarms in the alarm system negatively
affects the operator’s ability to distinguish between important safety-critical
alarms and routine process alarms, and they learn to treat some alarms as
low-priority alarms.
8) Standing alarms:
These alarms are continuously present on the alarm display and remain active for
very long periods of time. It provides a distraction for the operator in
effectively dealing with new alarm conditions that need attention.
[Note: EEMUA recommends no more than 10 standing alarms for facilities during
steady state operations.]
9) Repeated alarm shelving: If an
alarm is being shelved almost every single day then clearly there is some
problem that should be addressed. When there is a need to shelve an alarm (or several
alarms) for a long time, say a month or two, the alarm(s) should not be part of
main alarm list. Such scenarios indicate equipment malfunction issues or alarm
system design related problems.
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