Maintenance & Reliability worked example

Mean Time Between Maintenance with total operating time of 3,600 hr: a worked example

This worked example runs the mean time between maintenance numbers for a tougher week than the baseline: total operating time of 3,600 hr instead of the typical 7,200 hr. Measure mean time between maintenance actions by dividing operating time by planned and unplanned maintenance events.

The inputs for this scenario

  • Total operating time: 3,600 hr (the input this scenario stresses; the baseline uses 7,200)
  • Total maintenance actions: 30 actions (held at the documented default)
  • Normalization factor: 1 x (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: MTBM = total operating time รท total maintenance actions.
  • MTBM works out to 120 hr / action at these inputs, and this is the headline figure for the scenario.
  • Base Hours per Maintenance Action works out to 120 hr / action at these inputs.
  • Normalization Factor works out to 1 x at these inputs.
  • Maintenance Actions works out to 30 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where total operating time sits at 7,200 hr and the headline result is 240 hr / action, this scenario comes in 50% below the baseline at 120 hr / action.
  • Use it to benchmark maintenance demand across assets, justify crew sizing, and track whether reliability programs are reducing intervention frequency. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • MTBM: 120 hr / action (headline result)
  • Base Hours per Maintenance Action: 120 hr / action
  • Normalization Factor: 1 x
  • Maintenance Actions: 30 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Mean Time Between Maintenance calculator, set total operating time to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.