Availability Calculator
Ideal inherent steady availability or MTBF/(MTBF+MTTR), independently compatible operating/repair definitions; planned/logistic down time external. Actual independently established compatible SI units/model context; conditional arithmetic, not code compliance, engineering design or safe operation approval.
Description
Inherent steady availability compares operating time with operating plus repair time under matched definitions.
Inherent steady availability compares operating time with operating plus repair time under matched definitions.1
This tool evaluates the supplied MTBF and MTTR relation without including unspecified planned or logistics downtime.
When to use Availability Calculator
Use this tool to evaluate the supplied MTBF and MTTR relation without including unspecified planned or logistics downtime.
How to use Availability Calculator and how it works
- Prepare callerEstablishedMtbfHours, callerEstablishedMttrHours, with the units, conventions and assumptions below.
- Enter the required fields and run Availability Calculator.
- Read result.value using the output definitions below.
- Correct any rejected inputs and rerun; interpret the result within the stated model and its assumptions.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| callerEstablishedMtbfHours | Caller Established Mtbf Hours. Use the units and matching context stated in the calculation below. | number | Required; strictly positive; finite; other constraints below |
| callerEstablishedMttrHours | Caller Established Mttr Hours. Use the units and matching context stated in the calculation below. | number | Required; nonnegative; finite; other constraints below |
Supply positive MTBF and nonnegative MTTR in one time unit. Return MTBF/(MTBF+MTTR) as a dimensionless steady-state availability estimate. This does not include scheduled downtime or verify a renewal-process model.
availability=MTBF/(MTBF+MTTR) Apply the input ordering, units and branch conditions stated above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the calculated or selected fields below. | object |
| result.value | Dimensionless inherent steady-state availability estimate. | number |
{
"input": {
"callerEstablishedMtbfHours": 4,
"callerEstablishedMttrHours": 1
},
"output": {
"result": {
"value": 0.8
}
}
}Limitations and assumptions
The calculation uses the supplied observations and model inputs. It does not collect measurements, select a reference population or coefficient, or establish that the model applies to the actual case. The stated branch conditions and output units remain part of the result.
All fields require explicit values. Unexpected fields, wrong types, nonfinite numbers and sparse arrays are rejected. Alignment, bounds and supported-token rules are explained above; extremely large inputs or nonfinite results can also fail. Input errors differ from successful false comparisons, unavailable-domain flags and empty match lists.
Alternative or Complementary methods
Use Weibull Reliability Calculator for a complementary operation: A two-parameter Weibull survival model depends on a calibrated time scale and shape.
Use MTBF Reliability Calculator for a complementary operation: A repairable-system MTBF point estimate divides operating exposure by observed failures.
References
-
Availability Calculator — tool.io
Similar or alternative tools
- Weibull Reliability Calculator
A two-parameter Weibull survival model depends on a calibrated time scale and shape.
- MTBF Reliability Calculator
A repairable-system MTBF point estimate divides operating exposure by observed failures.