Heat Treatment, Furnaces & Thermal Processing worked example

Furnace Downtime Cost at 72% share of hourly cost actually incurred: a worked example in heat treatment, furnaces & thermal processing

Suppose share of hourly cost actually incurred falls to 72%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate furnace downtime cost from lost furnace hours, hourly downtime cost, capture percent, and fixed restart or service cost.

The inputs for this scenario

  • Furnace hours lost to downtime: 8 hr (held at the documented default)
  • Cost per idle furnace hour: 650 $ / hr (held at the documented default)
  • Share of hourly cost actually incurred: 72 % (the input this scenario stresses; the baseline uses 100)
  • Fixed restart, purge, or service charge: 1,200 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Captured furnace downtime cost = lost furnace hours × downtime cost rate × downtime cost capture.
  • Total furnace downtime cost works out to 4,944 $ at these inputs, and this is the headline figure for the scenario.
  • Downtime cost per lost hour works out to 618 $ / hr at these inputs.
  • Captured downtime loss works out to 3,744 $ at these inputs.
  • Fixed restart or service cost works out to 1,200 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share of hourly cost actually incurred sits at 100% and the headline result is 6,400 $, this scenario comes in 22.75% below the baseline at 4,944 $.
  • It multiplies lost furnace hours by an hourly downtime cost and a capture factor, then adds any fixed restart or service charge to give the total downtime cost of an event. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Total furnace downtime cost: 4,944 $ (headline result)
  • Downtime cost per lost hour: 618 $ / hr
  • Captured downtime loss: 3,744 $
  • Fixed restart or service cost: 1,200 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Furnace Downtime Cost calculator, set share of hourly cost actually incurred to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.