5 Tips for SCADA Alarm Management
- scadalrt
- Jan 8, 2024
- 5 min read
Updated: Jan 31, 2024
SCADA (Supervisory Control and Data Acquisition) systems are widely used in various industries, including manufacturing, food and beverage, water and wastewater, oil and gas, just to name a few. One of the most essential functions of a SCADA system is alarm notification. Providing alarms to the system operations team allows technicians to quickly adjust the process as needed and resolve the alarm condition. This is critical to reducing downtime or preventing catastrophes. Unfortunately, too many SCADA systems are implemented without effective alarm management practices in place. As a result, operators ultimately suffer from "Alarm Fatigue", which occurs when they become desensitized to alarms, which leads to decreased responsiveness. Let's discuss some tips for effectively managing SCADA alarms.
Table of Contents
Remove Nuisance Alarms
Arguably the most important step in managing your SCADA alarms is removing nuisance alarms. Nuisance alarms can be caused by a number of different scenarios. The most common causes are alarms that should be events, changes to process over time, equipment maintenance, and cascading alarms.
Alarms That Should Be Events
One of the most common types of nuisance alarms is an alarm that is really more of an event. It's important to categorize these conditions accordingly. An alarm is a condition that should warrant some action by a technician or operator to resolve the problem or abnormal condition. An event is an occurrence of a routine condition or system milestone. By reviewing alarms and recategorizing the appropriate alarms to events, nuisance alarms can be reduced significantly.
Changes to Process Over Time
When SCADA systems are initially commissioned, decisions about alarms are made based on the known process at the time of commissioning. However, SCADA systems last many years and it's quite common for the process that the system is monitoring to undergo changes during that timeframe. This can lead to the triggering of process alarms that used to warrant an alarm, but now can be removed completely. When receiving SCADA alarms, it's important to always ask yourself "is this alarm still relevant for this process"?
Equipment Maintenance
Most SCADA systems are alarming based on feedback from monitored equipment. This can be anything from motors or valves, to process variables like temperature or speed. This equipment or instrumentation requires regular maintenance or calibration. During this maintenance or calibration, the equipment may be placed into a state that creates an alarm condition, even though the cause of that alarm is not truly present. Some common examples if this would be equipment locked-out for repair, a generator running as a routine exercise, or an instrument being calibrated with minimum and maximum limits being simulated. While we can't prevent the need for maintenance, it's important to implement a solution in SCADA that allows equipment to be taken "out of service". This would provide visual representation that the displayed value should not be trusted, and will prevent nuisance alarms for the operations team.
Cascading Alarms
The term "cascading alarms" refers to alarms that occur because another alarm is active. Most controllers will use general or common alarms to represent an alarm when any alarm has occurred. This can be used for interlock logic or alarm lamp outputs. Unfortunately, it is commonly added to SCADA as an alarm. This results in multiple alarms occurring simultaneously for a single alarm condition. This can be evaluated by reviewing alarm summaries or alarm history to identify alarms that become active at the same time. These alarms can be reviewed and the redundant alarm can be removed from SCADA.
Expose Alarm Priority to Operations
Most SCADA platforms provide a priority or severity level that can be assigned to each alarm. This is generally a numerical value, most commonly ranging from 1-999. Most SCADA systems are developed without this priority being user-configurable for operations. They are configured during development and commissioning, and not updated during day-to-day operations. As a result, alarms exist with priority designations that the operations team would not consider accurate for the severity of the given alarm. Exposing alarm priority configuration to the user-interface will allow operators to routinely update alarms based on implied severity of that condition. This will allow for better filtering and escalation which will be discussed below.
Use SCADA Alarm Grouping
Most SCADA platforms provide a mechanism for alarm grouping. Generally, when an alarm is created, it's assigned to a default group. Most SCADA systems monitor different process areas or include different operational teams. If alarm groups aren't leveraged, users will receive notifications for an alarm that's not relevant to them. Even worse, they may acknowledge that alarm without taking accountability for resolution. It's critical that the process areas, operational teams, and all system alarms are reviewed to determine the necessary grouping.
Leverage Alarm Filtering and Banners
In general, SCADA alarms are viewed on some type of summary page. This page will contain all alarms regardless of priority or group. This can lead to a massive list of potentially hundreds of alarms. This can lead to operators missing critical alarms or accidentally acknowledging an alarm that should remain unacknowledged. An important consideration when managing SCADA alarms is how to filter alarm displays to allow operations to quickly identify relevant and critical alarms first. A couple important solutions involve creating filtering tools and the implementation of an alarm banner.
Alarm Filtering
An effective alarm summary page should always include tools for filtering and sorting alarms. Alarms should be able to be filtered by their priority and their group. This allows operations to quickly filter for the group of alarms that they are responsible for, and prioritize addressing the critical alarms first.
Alarm Banner
An alarm banner is an absolute must on any SCADA system, and it's rare to see a system without one. The primary objective of an alarm banner is visibility regardless of navigation. The alarm banner is usually located as a header or footer on the user-interface, and displays a short list of alarms. Unfortunately, there is an important consideration that is often missed in alarm banners. Because the banner only has enough space for a few alarms, it's important that this list doesn't fill up, or it will defeat the purpose of having the banner all together. In order to keep this list of alarms to a minimum, the alarm banner should be reserved for only active and unacknowledged alarms. This will clear the alarm from the banner once acknowledged even if the alarm condition is still active. Unfortunately, this is an important consideration that is often missed in alarm banners.
Effectively Notify and Escalate
SCADA alarm notification software is designed to connect to a SCADA platform and provide a remote alarm notification. The notification methods are generally SMS, voice, or email. The alarm notification software will have some type of contact list or schedule to escalate notifications to the appropriate person if the alarm condition stays active and unacknowledged. It's important to leverage an alarm notification software that automatically pulls alarms and their respective groups and priority from SCADA. Some alarm notification software requires manually adding or removing alarms from the software. This leads to alarms being added to SCADA that get missed when adding to the alarm notification software. It's also helpful to leverage an alarm notification software that provides flexibility in notification methods. Different people, groups, or times of day may prefer one notification method (SMS, voice, email) over another. Developing the appropriate list of contacts and their desired notification methods is crucial to effectively managing SCADA alarms.
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