THE NUMBERS, EXPLAINED
How to use this calculator.
One already-grouped outage per row; timestamps use a shared origin. Percentiles use the nearest-rank method; overlapping outages remain separate events.
Start with your inputs
Enter failure timestamps (elapsed minutes), recovery timestamps (elapsed minutes). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Failure timestamps (elapsed minutes) | 0,10,30 |
| Recovery timestamps (elapsed minutes) | 5,20,45 |
A worked example
With the example inputs above, repair durations (minutes) is 5, 10, 15. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Repair durations (minutes) | 5, 10, 15 |
| Mean repair time (minutes) | 10 |
| 90th percentile repair time (minutes) | 15 |
How this is calculated
Repair durations (minutes)
Subtract each failure timestamp from its matching recovery.
Mean repair time (minutes)
Average the repair durations.
90th percentile repair time (minutes)
Sort durations and select rank ceil(0.9 times count).
Symbols and units
- a
- Failure timestamps (elapsed minutes)
- b
- Recovery timestamps (elapsed minutes)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
One already-grouped outage per row; timestamps use a shared origin. Percentiles use the nearest-rank method; overlapping outages remain separate events.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Repair durations (minutes); Mean repair time (minutes); 90th percentile repair time (minutes). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: One already-grouped outage per row; timestamps use a shared origin. Percentiles use the nearest-rank method; overlapping outages remain separate events.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
NumPy Quantile — inverted_cdf discrete quantile method ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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