Maintenance & Reliability worked example
Failure Rate with number of failures of 30 failures: a worked example
Push number of failures up to 30 failures and the picture changes. This example computes every intermediate figure at that operating point. Use it when reliability models or mission-time calculations need a frequency of failure rather than hours between failures.
The inputs for this scenario
- Number of failures: 30 failures (raised for this scenario; the documented default is 12)
- Total operating hours: 7,200 hr (unchanged)
- Reporting factor: 1 x (unchanged)
Working through the calculation
- Applying the documented formula (Failure rate = number of failures รท total operating hours) to the inputs above produces each figure below.
- At this operating point the engine returns 0 failures / hr for failure rate, the number this scenario is built around.
- At this operating point the engine returns 0 failures / hr for base failures per hour.
- At this operating point the engine returns 1 x for reporting factor.
- At this operating point the engine returns 7,200 value for operating hours.
How this compares with the baseline
- Against the tool's baseline example, where number of failures sits at 12 failures and the headline result is 0 failures / hr, this scenario comes in 150% above the baseline at 0 failures / hr.
- It computes failures per operating hour and scales that base rate by a reporting factor to express it in FIT, failures per million hours, or any basis you choose. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.
Results at a glance
- Failure Rate: 0 failures / hr (headline result)
- Base Failures per Hour: 0 failures / hr
- Reporting Factor: 1 x
- Operating Hours: 7,200 value
Run it with your numbers
- Every input above is editable in the live Failure Rate calculator, which recalculates instantly and can be shared with the inputs intact.
Last reviewed 2026-05-12.