Calculator
Example Data Table
| Team | Period | Total | Success | Failed | Rollbacks | Hotfixes | Success Rate |
|---|---|---|---|---|---|---|---|
| Platform | 2026-02-01 → 2026-02-28 | 120 | 118 | 1 | 1 | 0 | 98.33% |
| Payments | 2026-02-01 → 2026-02-28 | 75 | 73 | 1 | 0 | 1 | 97.33% |
| Mobile | 2026-02-01 → 2026-02-28 | 42 | 41 | 0 | 0 | 1 | 97.62% |
These rows are illustrative. Your real rates depend on how you classify failures, rollbacks, and hotfixes.
Formula Used
- Success Rate (%) = (Successful ÷ Effective Total) × 100
- Change Failure Rate (%) = ((Failed + Rollbacks + Hotfixes) ÷ Effective Total) × 100
- Error Budget Remaining = (Effective Total × (1 − Target/100)) − (Effective Total − Successful)
- Trend (pp) = Current Success Rate − Previous Success Rate
How to Use This Calculator
- Enter your deployment counts for the selected period.
- Choose whether maintenance deployments should be excluded.
- Set a target success rate aligned with your release policy.
- Optionally add the previous period success rate for trend.
- Click Calculate to see metrics and a report table.
- Use Download CSV or Download PDF for sharing.
FAQs
1) What counts as a successful deployment?
A deployment that completes and delivers the intended change without rollback, hotfix, or emergency remediation. Align definitions across teams for consistent reporting.
2) Should rollbacks be included as failures?
Usually yes, because they represent an unsuccessful change reaching production. This calculator also includes rollbacks inside Change Failure Rate for a broader reliability view.
3) What is Change Failure Rate and why track it?
Change Failure Rate measures deployments that caused incidents or required fixes. It’s widely used to show release quality beyond simple success counts.
4) Why exclude maintenance deployments?
Maintenance can inflate totals without reflecting feature delivery risk. Excluding them can make operational success rate more meaningful for engineering outcomes.
5) How should I set a target success rate?
Start with your risk tolerance and current baseline. Many teams choose 99%+ for mature pipelines, then improve gradually with better testing and rollout controls.
6) What does “error budget remaining” mean here?
It estimates how many unsuccessful deployments you can still tolerate while meeting the target. Negative values indicate the target has already been exceeded by failures.
7) How often should I calculate and share this report?
Weekly for fast feedback, or monthly for leadership summaries. Keep the period consistent so trends and comparisons stay reliable across releases.