A well-designed alarm system increases operational awareness, alerts personnel to abnormal operating conditions and allows them to prevent or minimize process disruptions. However, inefficient and improper alarm management can lead to a flood of unimportant information or even worse, to false positives that distract operators from responding to important operational alarms. Alarm management involves reviewing, classifying and prioritizing alarms to ensure they meet the philosophy defined in the system. It also includes monitoring the system and assessing its performance against goals.
It’s a continuous improvement process that can provide enormous value to an organization, Sands said. For example, one large plant estimated that a well-managed alarm program saved $10 million a year in avoidable shutdowns, lost production and off-quality product. That’s a big return on a relatively small investment, he added.
A successful alarm management program begins with establishing an alarm management philosophy, followed by developing and training personnel on the alarm management policy. Then the process is implemented with a series of steps: identifying non-alarm conditions; rationalizing alarms to reduce their frequency and severity; monitoring the system to identify opportunities for improvement; and continually improving the program.
The most important thing, he says, is ensuring that an alarm is truly needed and that it will have the desired impact on the operator’s action. A good alarm is clear, concise and informative; provides the necessary context for interpreting and responding to the alarm; doesn’t disrupt normal operations; and requires the correct action from the operator.
Alarms that are not needed can be eliminated through suppression or shelving, which hide the alarm from the display and allow it to remain suppressed or out of service according to specific rules. An alarm can also be put out of service manually by a plant engineer.
It’s also important to monitor control loop performance, he says. This can be done with automated software tools that are built into modern DCS answering & messaging services systems. These tools can automatically track and report on the health of a control loop and provide valuable performance metrics to engineers.
Alarm management can be a regulatory requirement, he says, depending on the industry and the country. For example, facilities regulated by the Occupational Safety and Health Administration OSHA can use the ISA-18 standard or IEC 62682 as recognized and generally accepted good engineering practice. The EPA and Food and Drug Administration also have requirements that can be met using these standards. The standards can also help companies comply with Seveso directives or British Petroleum’s EEMUA 191 guideline. They can also be used to meet FDA Current Good Manufacturing Practices. ISA-18 and IEC 62682 can also be used for a number of compliance-related reasons, including meeting ISO 9001 quality requirements.