MAR-APR 2018

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18 INTECH MARCH/APRIL 2018 WWW.ISA.ORG By Bridget Fitzpatrick A larm systems are critical for facilitat- ing process safety, ensuring efficient op- erations, and maintaining quality. Alarm management has been broadly implemented in the process industries over the past 20 to 30 years. If your facility has not embraced this fundamental aspect of automation and control, time is wast- ing! For sites that started in the early days with the ASM Consortium TM work of the 1990s, or later with the publication of ISA-18.2 in 2009, alarm management concepts are likely well integrated or even commonplace. One of the common phenomena of alarm man- agement is an initial gain in performance, fol- lowed by a gradual erosion of benefits. A major root cause of this variation is that most processes continually change—perhaps more often than we think. Changes to raw materials and product specifications, debottlenecking, new environ- mental regulations, and plant trials may affect alarm management. It is important to understand that alarm management is a never-ending effort. Managing the life-cycle aspects is as critical as getting the correct initial design or rationalization. One concept that can help manage the work pro- cess is alarm class or classification. What is an "alarm class"? As stated in ANSI/ISA-18.2-2016, Management of Alarm Systems for the Process Industries, an alarm class is a "group of alarms with a common set of alarm management requirements (e.g., testing, training, monitoring, and audit requirements)." One type of alarm class is a safety critical alarm, which, according to ANSI/ISA-18.2-2016, is defined as "an alarm that is classified as critical to process safety for the protection of human life or the environment." An alarm may belong to more than one class. The alarm philosophy is required to provide a definition for alarm classes. However, like require- ments in many standards, the specific definition and requirements of alarm classes are left to the Leveraging classes Alarm management life cycle

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