Industrial Cybersecurity & OT Risk worked example

PLC Recovery Time at 40% validation and restart allowance: a worked example

This scenario runs the plc recovery time calculation on the strong side: 40% validation and restart allowance, with every other input held at its documented default. Use it when planning recovery from failed hardware, corrupted logic, backup restore, or cyber incident recovery exercises.

The inputs for this scenario

  • PLCs or controller projects to recover: 12 controllers (unchanged)
  • PLC recovery completion rate: 0.8 controllers / hr (unchanged)
  • Validation and restart allowance: 40 % (raised for this scenario; the documented default is 35)

Working through the calculation

  • Applying the documented formula (Base PLC recovery time = PLCs or controller projects to recover รท PLC recovery completion rate) to the inputs above produces each figure below.
  • At this operating point the engine returns 21 hr for required plc recovery time, the number this scenario is built around.
  • At this operating point the engine returns 15 hr for base plc recovery time.
  • At this operating point the engine returns 40 % for validation and restart allowance.
  • At this operating point the engine returns 0.8 pieces / min for plc recovery completion rate.

How this compares with the baseline

  • Against the tool's baseline example, where validation and restart allowance sits at 35% and the headline result is 20.25 hr, this scenario comes in 3.7% above the baseline at 21 hr.
  • Use it when building or stress-testing an OT recovery plan, sizing a restoration crew, or setting a controller RTO. 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 PLC recovery time: 21 hr (headline result)
  • Base PLC recovery time: 15 hr
  • Validation and restart allowance: 40 %
  • PLC recovery completion rate: 0.8 pieces / min

Run it with your numbers

  • Every input above is editable in the live PLC Recovery Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.