Industrial Cybersecurity & OT Risk worked example

Cyber Recovery Spares Buffer with daily recovery spares consumption rate of 1 units / day: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop daily recovery spares consumption rate to 1 units / day, then walk the calculation through step by step. Estimate required recovery spares inventory for cyber recovery using daily demand, replenishment lead time, and safety stock.

The inputs for this scenario

  • Daily recovery spares consumption rate: 1 units / day (the input this scenario stresses; the baseline uses 2)
  • Recovery spares replenishment lead time: 21 days (held at the documented default)
  • Recovery spares safety stock held: 12 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Cyber recovery spares cycle stock = daily recovery spares demand × recovery spares replenishment lead time.
  • Protected days of supply works out to 0 days at these inputs, and this is the headline figure for the scenario.
  • Unprotected days works out to 0.05 days at these inputs.
  • Inventory works out to 1 pieces at these inputs.
  • Daily usage works out to 21 pieces / day at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where daily recovery spares consumption rate sits at 2 units / day and the headline result is 0.01 days, this scenario comes in 50% below the baseline at 0 days.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to daily recovery spares consumption rate, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes steady daily demand and a known lead time; a large simultaneous-loss event (every HMI on a line wiped at once) is a spike this cycle-stock model doesn't capture and should be planned for separately.

Results at a glance

  • Protected days of supply: 0 days (headline result)
  • Unprotected days: 0.05 days
  • Inventory: 1 pieces
  • Daily usage: 21 pieces / day

Run it with your numbers

  • To rerun this with your own numbers, open the live Cyber Recovery Spares Buffer calculator, set daily recovery spares consumption rate to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.