IIoT, SCADA & Edge Connectivity worked example

Alarm Rationalization Workload at 40% documentation, moc, and operator validation allowance: a worked example

This scenario runs the alarm rationalization workload calculation on the strong side: 40% documentation, moc, and operator validation allowance, with every other input held at its documented default. Use it when an operations or alarm management lead is sizing a rationalization sprint to drive operator alarm rate down to ISA-18.2 EEMUA-191 targets.

The inputs for this scenario

  • Alarms to rationalize: 3,500 alarms (unchanged)
  • Team review rate: 10 alarms / hr (unchanged)
  • Documentation, MoC, and operator validation allowance: 40 % (raised for this scenario; the documented default is 35)

Working through the calculation

  • Applying the documented formula (Base alarm rationalization hours = alarm count รท team review rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 490 hr for required alarm rationalization hours, the number this scenario is built around.
  • At this operating point the engine returns 350 hr for base alarm rationalization hours.
  • At this operating point the engine returns 40 % for documentation, moc, and validation allowance.
  • At this operating point the engine returns 10 pieces / min for team review rate.

How this compares with the baseline

  • Against the tool's baseline example, where documentation, moc, and operator validation allowance sits at 35% and the headline result is 473 hr, this scenario comes in 3.7% above the baseline at 490 hr.
  • Use it when scoping an alarm rationalization project, building a DCS/SCADA migration plan, or justifying headcount for an ISA-18.2 alarm management initiative. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Required alarm rationalization hours: 490 hr (headline result)
  • Base alarm rationalization hours: 350 hr
  • Documentation, MoC, and validation allowance: 40 %
  • Team review rate: 10 pieces / min

Run it with your numbers

  • Every input above is editable in the live Alarm Rationalization Workload calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.