The first phase should establish reliable log ingestion and storage—log management—before attempting advanced detection content or automation. A SIEM is only as effective as the data it receives. In a complex environment, initial success depends on building a stable pipeline: collecting logs from priority sources, normalizing timestamps, ensuring consistent parsing, defining retention, and validating data quality (completeness, latency, duplication, and integrity). Without this foundation, analytics will produce blind spots, false positives, and missed detections, and automation may take disruptive actions based on incomplete data. UEBA and security analytics are valuable but require sufficient historical, high-quality telemetry to build baselines and correlations. Similarly, incident response automation should come after the organization has validated detections, tuning, and operational workflows; otherwise, playbooks may amplify errors at scale. A phased approach typically starts with identifying key data sources (identity, endpoint, network, cloud), onboarding them into log management, confirming visibility and schema consistency, and only then layering detection rules, correlations, and response workflows. Therefore, setting up log management first is the correct starting phase for a low-risk, high-success SIEM deployment.