Wednesday, May 18, 2016

9 Signs Your SCADA Alarm System is Ineffective

Alarms are one of the most critical components of industrial operations and the primary means of alerting the control room operators of abnormal situations. Effective handling of alarms is crucial to the plant’s safety, productivity and profitability; however, many manufacturing facilities do not have a long-term, well-defined alarm management program in place. In most cases the approach remains reactive rather than proactive.

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. 
[Note: The EEMUA guidelines suggest that there should be less than 30 shelved alarms in an efficient industrial facility at any given time.]

In the next blog, I will talk about the key alarm management improvement strategies that should be considered to build a successful alarm management program.

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