ANSI/ISA-18.2, Management of Alarm Systems for the Process Industries, changed the world of alarm management when first published in 2009 with the introduction of activities grouped into the alarm management life cycle. That life cycle has since become globally recognized, as the standard has been adopted by the International Electrotechnical Commission and found wide use across the process industry sectors.
Drawing on knowledge gained from six years of extensive application throughout industry, the ISA18 committee has completed an updated version of the standard that has been approved by the American National Standards Institute as ANSI/ISA-18.2-2016. This revision was led by ISA18 co-chairs Donald Dunn, director of engineering in the Amarillo Division, Phillips 66, and Nicholas Sands, global alarm management leader for DuPont and a manufacturing technology fellow for DuPont Protection Solutions.
Among the key changes in the new version, point out Sands and Dunn, are stronger requirements for control systems to have the functions to support good alarm management practices, new requirements for package systems, such as compressors and heat trace systems, and clarifications in terminology.
The ISA18 committee has published and continues to develop ISA technical reports that provide guidance in using the standard. Three new ISA18 technical reports are expected to be published this year covering alarm philosophy, alarm management for utilizing packaged systems, and alarm identification and rationalization.
The latter technical report, ISA-TR18.2.2-2016, is expected to be published in July 2016. It will provide guidance, rationale, and examples for the identification and rationalization of life-cycle stages from ANSI/ISA-18.2 per the following:
- Identification: a general term for the different methods that can be used to determine the possible need for an alarm or a change to an alarm. The identification stage is the input point of the alarm life cycle for recommended alarms or alarm changes. Identified alarms are an input to rationalization.
- Rationalization: encompasses several significant activities, including alarm justification, documentation, prioritization, and classification. In justification, existing or potential alarms are systematically compared to the criteria for alarms set forth in the alarm philosophy. If the proposed alarm meets the criteria, then the alarm type, set point, cause, consequence, and operator action are documented. The alarm is prioritized and classified according to the philosophy. Classification encompasses assigning alarms to a group or class defining certain administrative requirements. These activities are often combined into a single rationalization activity. They do not need to be conducted in separate sessions.
Previously published ISA18 technical reports include:
- ISA-TR18.2.3-2015, Basic Alarm Design, provides guidance on implementing the practices set forth in ANSI/ISA-18.2. Following the life-cycle model of ANSI/ISA-18.2, the document assumes that alarms to be addressed in basic alarm design have completed rationalization, where attributes such as alarm set point and priority have been defined.
- ISA-TR18.2.5-2012, Alarm System Monitoring, Assessment, and Auditing, provides guidance on the use of alarm system analysis for both ongoing monitoring and periodic performance assessment. Monitoring, assessment, and audit are essential to achieving and maintaining the performance objectives of the alarm system. These activities can identify improvement opportunities in the other life-cycle stages, such as philosophy, rationalization, detailed design, implementation, operation, maintenance, and management of change.
- ISA-TR18.2.4-2012, Enhanced and Advanced Alarm Methods, helps users to evaluate when to use enhanced and advanced alarming methods, what benefits they can achieve, and what challenges and costs to expect. Per ANSI/ISA-18.2, enhanced and advanced alarm methods typically go beyond the basic methods and techniques that are usually, or at least initially, applied. Although significant improvement in alarm system function and performance can usually be made by following the basic alarming methods and principles, in some cases they may not be sufficient to achieve the goals for performance and operator guidance stated in the alarm philosophy.
- ISA-TR18.2.6-2012, Alarm Systems for Batch and Discrete Processes, covers the application of alarm management principles in ANSI/ISA-18.2 to batch and discrete processes. The general principles and techniques described are intended for use in the life-cycle management of an alarm system based on programmable electronic controller and computer-based human-machine interface technology. Following the guidance will help to identify and address alarm specification, design, implementation, and management opportunities that are important to batch and discrete processes. It will also help minimize the generation of nuisance alarms that could complicate and frustrate an operator's awareness, understanding, and response to abnormal situations.
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