Developing an Alarm Help strategy begins with understanding your objectives for implementing it. The most common objectives for using Alarm Help are the following:
For use as an Operator response tool
Alarm Help makes key information from alarm rationalization (such as cause, consequence, time to respond, and suggested operator action) available. Operators can use this information to diagnose alarms and their causes and determine the best corrective action. Alarm Help improves upon and supplements written documents.
For use as a basic stand-alone ISA-18.2 compliant Master Alarm Database
ANSI/ISA-18.2-2009 Management of Alarm Systems for the Process Industries (ISBN: 978-1-936007-19-6) defines minimum requirements for a master alarm database, which is by definition the authorized list of rationalized alarms and associated attributes. By default the six configurable Alarm Help properties in the DeltaV system correspond to the minimum required attributes.
To complement an external ISA-18.2 Master Alarm Database or local alarm response policy
There are many reasons to deploy an external master alarm database. There may be multiple control system versions, non-DeltaV control systems or other alarm sources, making a single site-wide database supported by a common external set of management processes ideal. Alarm Help is tightly integrated into the DeltaV Operator interface, so it is most beneficial to selectively feed it from an external database with information that has the greatest ‘in-context’ value to the operators, optimizing the other fields of the external database to serve a wider audience of alarm system stakeholders. Bulk import/export features ease transfer of information between an external database and DeltaV Alarm Help.
For use as an Operator knowledge capture system
Alarm causes and operator responses determined previous to system commissioning may be incomplete or need modification based on real-world operating conditions. For these and other reasons some sites may allow knowledgeable operators to add/edit Alarm Help properties directly from the operating environment, and enable them (or not) to distribute these changes throughout the system. Parameter level granularity allows some fields to be used for Operator-knowledge capture, reserving others for read-only use.
After you have determined what your objectives design your Alarm Help implementation. Alarm Help design is most efficiently accomplished early in the system configuration process. Some items to consider during design are:
What alarm functional classifications do you need? Changing functional classification for alarms requires full download of alarm containers so deciding classifications early minimizes disruptions to system operation later.
Which alarm text fields are you going to use? What type of information do you need to convey to operators and other users? What type information (if any) do you want to capture from your users? The labels on these fields are configurable and their contents are free text so the fields can be used for any type of information that is meaningful in your implementation.
Who is authorized to create or edit and download Alarm Help from the Alarm Help View and Edit Application? The Alarm Help security keys allow assigning keys to individual Alarm Help items so that you can open one or more Alarm Help text fields to allow entry of experience in dealing with alarms or suggestions for alarm configuration changes.