Glossary

Terms

CFR (Change Failure Rate)

Share of deployments causing a failure. One of the four DORA keys.

DF (Deployment Frequency)

How often production receives a change. DORA throughput metric.

LTC (Lead Time for Changes)

Time from first commit to production-ready. DORA throughput metric.

MTTR (Mean Time to Restore)

Time from incident detection to service restoration. DORA stability metric.

MTTD (Mean Time to Detect)

Time from incident occurrence to detection. SRE practice; not a DORA metric.

MTBF (Mean Time Between Failures)

Average uptime between failures. Reliability metric; not a DORA metric.

DXI (Developer Experience Index)

DX Core 4 survey instrument. Captures ease-of-flow, frustrations, capability ratings.

SPACE

Five-dimension developer-productivity framework: Satisfaction, Performance, Activity, Communication, Efficiency (Forsgren, Storey, Maddila et al, ACM Queue 2021).

DORA

DevOps Research and Assessment. Originated by Forsgren, Humble, Kim; now run by the DORA team at Google Cloud.

DX Core 4

Four-metric framework layering DXI, Diff Throughput, CFR, Retention. Published by Abi Noda / DX, 2024.

Fix-only deploy

A forward-fix deploy that exists only to patch the previous failed deploy. DORA guidance is to exclude from the CFR denominator.

Elite / High / Medium / Low

Legacy DORA tier labels (pre-2024). Dropped in 2024 in favour of percentile distribution framing.

Primary sources: DORA Four Keys DORA Four Keys2024 for DORA terms; ACM Queue SPACE paper SPACE (ACM Queue 2021)2021 for SPACE; DX Core 4 publication DX Core 42024 for Core 4 / DXI.