Aftermarket, Field Service & Service Parts worked example

Mean Time to Repair (MTTR) at 25% diagnosis and verification allowance: a worked example

This worked example runs the mean time to repair (mttr) numbers for a tougher week than the baseline: 25% diagnosis and verification allowance instead of the typical 35%. Estimate average repair time from repair tasks, completion pace, and allowance for diagnosis, parts waiting, or verification.

The inputs for this scenario

  • Repair tasks or service events: 96 tasks (held at the documented default)
  • Repair completion pace: 0.42 tasks/min (held at the documented default)
  • Diagnosis and verification allowance: 25 % (the input this scenario stresses; the baseline uses 35)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base repair time = repair tasks รท repair completion pace.
  • Mean time to repair estimate works out to 286 repair hr at these inputs, and this is the headline figure for the scenario.
  • Base repair time works out to 229 repair hr at these inputs.
  • Diagnosis and verification allowance works out to 25 % at these inputs.
  • Repair completion pace works out to 0.42 tasks/min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where diagnosis and verification allowance sits at 35% and the headline result is 309 repair hr, this scenario comes in 7.41% below the baseline at 286 repair hr.
  • Use it when scoping field-service response, setting maintenance SLA targets, or sizing the labor and time budget for a class of repairs. 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

  • Mean time to repair estimate: 286 repair hr (headline result)
  • Base repair time: 229 repair hr
  • Diagnosis and verification allowance: 25 %
  • Repair completion pace: 0.42 tasks/min

Run it with your numbers

  • To rerun this with your own numbers, open the live Mean Time to Repair (MTTR) calculator, set diagnosis and verification allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.