Failed Deployment Recovery Time Calculator
Mean time to restore service after a change that failed.
In short
Formula: Recovery time = Total restore time after failed changes / Number of failed changes
What this calculator does
The DORA failed deployment recovery time, counted over failed changes only. It is deliberately a different population from incident mean time to repair, which counts every incident whatever caused it.
Use it to turn Total time to restore service after failed changes, Failed changes counted into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Total time to restore service after failed changes
- — Sum of the restore times following failed deployments in the period..
- Failed changes counted
- — Number of failed deployments those hours cover..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
Recovery time = Total restore time after failed changes / Number of failed changes.
Inputs used: Total time to restore service after failed changes, Failed changes counted.
Edge handling: Total time to restore service after failed changes is required.; Total time to restore service after failed changes cannot be negative.; Total time to restore service after failed changes must be no more than 1000000000000.; Failed changes counted is required.; Failed changes counted cannot be negative..
Worked example
9.5 hours of recovery across 5 failed deployments
- Start with Total time to restore service after failed changes: 9.5, Failed changes counted: 5.
- Apply the method: Recovery time = Total restore time after failed changes / Number of failed changes.
- This counts failed changes only, which is not the same population as all incidents.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this failed deployment recovery time calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: DevOps Research and Assessment, Google Cloud — DORA metrics: the four keys
Last reviewed:
Common questions
Where does this formula come from?
Deployment frequency is deployments to production divided by the length of the period; change failure rate is the share of changes to production that cause degraded service requiring remediation; failed deployment recovery time is the time taken to restore service after such a change. See the source link on this page.
What kind of calculation is this?
The mean time to restore service following a failed deployment. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
What are its limits?
Arithmetic over the figures entered — it cannot tell whether the underlying monitoring, incident records or change records are complete. A mean over a short period, or over few events, is a weak description of behaviour. Covers failed changes only, so it is not interchangeable with incident mean time to repair.
How do I use the Failed Deployment Recovery Time Calculator?
Enter the required values for Total time to restore service after failed changes, Failed changes counted. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Failed Deployment Recovery Time Calculator use?
Recovery time = Total restore time after failed changes / Number of failed changes The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the Failed Deployment Recovery Time Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
The mean time to restore service following a failed deployment.
The question it answers: What is our deployment rate, what share of changes fail, and how long does recovery take?
The formula
Recovery time = Total restore time after failed changes / Number of failed changes
- Tr — Total restore time
- (h). Sum of the restore times following failed deployments.
- n — Failed changes
- (count). Failed deployments those hours cover.
Units: Hours in, hours and minutes out.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
The DORA failed deployment recovery time, counted over failed changes only. It is deliberately a different population from incident mean time to repair, which counts every incident whatever caused it.
Assumptions built into the result
- Mathematical: The figures entered all cover the same measurement period.
- Mathematical: Incidents, changes and requests are counted consistently with the definition the team has written down.
- Mathematical: A failed change is identified by the same rule used for the change failure rate.
Figures this calculator will never guess for you
- No target, benchmark, industry average or performance band is supplied for any figure.
- A definition is never presented as a goal: the availability formula is not an availability target, and the change failure rate formula is not an acceptable failure rate.
- No DORA performance band is stated, and the result is not placed in one.
Limitations
- Arithmetic over the figures entered — it cannot tell whether the underlying monitoring, incident records or change records are complete.
- A mean over a short period, or over few events, is a weak description of behaviour.
- Covers failed changes only, so it is not interchangeable with incident mean time to repair.
Source and version
- Standard or reference
- DORA metrics — the four keys — DORA (Deployment frequency is deployments to production divided by the length of the period; change failure rate is the share of changes to production that cause degraded service requiring remediation; failed deployment recovery time is the time taken to restore service after such a change.)
- Published source
- DevOps Research and Assessment, Google Cloud — DORA Metrics Guide
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Academic
- Applies to
- Currency
- The result is a ratio or index, so it does not depend on currency.
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