Industrial Cybersecurity & OT Risk worked example

OT Change Window Cost at 32% share of production affected during window: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop share of production affected during window to 32%, then walk the calculation through step by step. Estimate cost of an OT cyber maintenance or change window using window hours, cost per hour, affected scope, and fixed preparation cost.

The inputs for this scenario

  • OT change window duration: 8 hr (held at the documented default)
  • Production cost per change window hour: 12,500 $ / hr (held at the documented default)
  • Share of production affected during window: 32 % (the input this scenario stresses; the baseline uses 45)
  • Fixed planning and validation cost: 12,000 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Variable OT change window cost = OT change window hours × cost per change window hour × affected production scope.
  • Total OT change window cost works out to 44,000 $ at these inputs, and this is the headline figure for the scenario.
  • Cost per change window hour works out to 5,500 $ / hr at these inputs.
  • Variable OT change window cost works out to 32,000 $ at these inputs.
  • Fixed planning and validation cost works out to 12,000 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share of production affected during window sits at 45% and the headline result is 57,000 $, this scenario comes in 22.81% below the baseline at 44,000 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to share of production affected during window, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It models direct downtime and fixed effort; it does not capture knock-on costs like missed delivery penalties, scrap from restart, or the risk cost of not making a security change.

Results at a glance

  • Total OT change window cost: 44,000 $ (headline result)
  • Cost per change window hour: 5,500 $ / hr
  • Variable OT change window cost: 32,000 $
  • Fixed planning and validation cost: 12,000 $

Run it with your numbers

  • To rerun this with your own numbers, open the live OT Change Window Cost calculator, set share of production affected during window to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.