3.5.2

Are human factors, capabilities and limitations explicitly taken account for when designing the alarm system?

Some of the key factors to be taken account of are:

  1. Number of background alarms should be few (Suggested- EEMUA: fewer than one per 5 minutes)
  2. Standing alarms should be few (Suggested from EEMUA: fewer than 10 in normal operations)
  3. Alarm flooding should be reduced (Suggested from EEMUA: fewer than 10 in ten minutes after upset)This should be documented.

The design should ensure that the alarm system remains usable in all process conditions, by ensuring that unacceptable demands are not placed on operators by exceeding their cognitive capabilities.

Comments/Recommendations

YA-711, point 1, p. 7EEMUA 191.
DC: Applicable to the DC