Four metrics that correlate with high organizational performance (revenue, share price, goal achievement). From the Accelerate State of DevOps research. | Metric | Definition | |--------|-----------| | **Lead time for changes** | Time from commit to production deployment | | **Deployment frequency** | How often deployments to production occur | | **Change failure rate** | % of changes that cause impaired service or require rollback/emergency fix | | **MTTR** (Mean Time to Restore) | Time to restore service after an unplanned outage or impairment | ## Why These Four They measure both *speed* (lead time, deploy frequency) and *stability* (CFR, MTTR). High performers score well on all four simultaneously — confirming that speed and quality are not trade-offs (see [[Three Myths About IaC and Change]]). ## Application to IaC The three core IaC practices (define as code, continually test/deliver, build small/simple) are directly aimed at improving these metrics: - Defining everything as code → enables consistent, automated deployments → improves lead time and deploy frequency - Continual testing → catches failures earlier → reduces change failure rate - Small, simple, independently deployable pieces → limits blast radius → improves MTTR --- *Source: [[Infrastructure as Code, 3rd Edition — Kief Morris]] (Kief Morris, O'Reilly 2025) — Ch 1 — What Is Infrastructure as Code?*