Maintenance & Reliability worked example

Annual Downtime Cost with unplanned downtime events per year of 70 events / yr: a worked example

This scenario runs the annual downtime cost calculation on the strong side: unplanned downtime events per year of 70 events / yr, with every other input held at its documented default. Use it when a plant needs one yearly downtime-loss figure for budgeting, capital requests, or reliability strategy review.

The inputs for this scenario

  • Unplanned downtime events per year: 70 events / yr (raised for this scenario; the documented default is 28)
  • Average financial loss per downtime event: 42,000 $ / event (unchanged)
  • Annual fixed overhead absorbed during downtime: 85,000 $ (unchanged)
  • Annual contract penalty and lost-service exposure: 60,000 $ (unchanged)

Working through the calculation

  • Applying the documented formula (Event-driven annual downtime loss = downtime events per year × average cost per event) to the inputs above produces each figure below.
  • At this operating point the engine returns 3,085,000 $ / yr for annual downtime cost, the number this scenario is built around.
  • At this operating point the engine returns 44,071 $ / event for cost per downtime event.
  • At this operating point the engine returns 2,940,000 $ for event-driven downtime cost.
  • At this operating point the engine returns 145,000 $ for fixed overhead and penalty.

How this compares with the baseline

  • Against the tool's baseline example, where unplanned downtime events per year sits at 28 events / yr and the headline result is 1,321,000 $ / yr, this scenario comes in 134% above the baseline at 3,085,000 $ / yr.
  • Use it when building a maintenance budget, a reliability project business case, or a TPM justification. 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

  • Annual Downtime Cost: 3,085,000 $ / yr (headline result)
  • Cost per Downtime Event: 44,071 $ / event
  • Event-Driven Downtime Cost: 2,940,000 $
  • Fixed Overhead and Penalty: 145,000 $

Run it with your numbers

  • Every input above is editable in the live Annual Downtime Cost calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.