We can consider several levels of maturity.
Level 1 — Collection
The company collects the logs.
Level 2 — Centralization
The logs are grouped together.
Level 3 — Alerting
Some rules generate alerts.
Level 4 — Correlation
Several events are analyzed together.
Level 5 — Threat Detection
The detections are built around attack scenarios.
Level 6 — Threat Hunting
Analysts are actively looking for suspicious behavior.
Level 7 — Automation
Some responses are automated.
Level 8 — Continuous Improvement
Detection systems are regularly tested, measured, and improved. The level of maturity naturally depends on the context and resources of the organization.