Step 1 — Service & SLI Definition

Throughput Volume of requests processed per time unit.

Quality Fraction of requests served at full quality (no degraded fallback). Correctness Fraction of outputs that are correct (pipelines, batch, calculations).

Coverage Fraction of expected records actually processed (ETL, batch ingestion). Durability Fraction of data confirmed intact over time (storage, object stores). Freshness Fraction of time data was fresh (binary gauge: 1=fresh, 0=stale).