Design Pattern: PF(3) Primary level of detail


Within his area of responsibility and authority, the human operator needs to comprehend sets of incoming alarms displayed by alarm displays. In particular, the human operator would like to take a look into his entire operator's area of responsibility and know the status of the controlled process.


The human operator needs to get an overview of the status of the controlled process control process in order to know whether this process is operating well.


Use a first level of detail of alarm information that shows the broadest available view of the elements or spatial area under a single human operator's control. It is a big picture at-a-glance view of the status of the controlled process. It can incorporate a combination of separate alarm visual displays formats and integrated displays in which alarm information is integrated into the process displays. However, they are not necessarily a pictorial. They may be mostly a tabular listing of important status and summary information, with trends to help provide the big picture. All irrelevant information should be removed from this level to avoid information overload.

Known uses
Fig1. ASM-style primary level display
Fig2. ISA-style primary level display system developed by Siemens

A primary level of detail of alarm information allows communicating to the operator whether or not the controlled process is operating well. (Rothenberg, D. H. (2009). Alarm management for process control: A best-practice guide for design, implementation, and use of industrial alarm systems McGraw-Hill Education.)