Microsoft Purview compliance portal: Purview Information Protection | Classifier Simulation Mode (Health Monitoring)

Microsoft Purview introduces Classifier Simulation Mode, allowing admins to test custom classifiers on production data before publishing. Available via the compliance portal, it helps reduce false positives and improve performance. Rollout starts early November 2025, with health insights and optional simulation controls for admins. Introduction Microsoft Purview is introducing Classifier Simulation Mode, the first phase of the broader Classifier Health Monitoring Platform. This new capability allows admins to test and validate custom classifiers on production data before publishing. Simulation Mode enables admins to optimize classifier logic before deployment, helping in reducing false positives, scanning latency, and noisy matches. Admins will access simulation controls and classifier health insights directly in the Microsoft Purview compliance portal, making it easier to monitor and improve classifier performance in one centralized location. This message is associated with Roadmap ID 523201. When this will happen: Targeted Release (Worldwide): Rollout begins early November 2025, completes by early December 2025. General Availability (Worldwide): Rollout begins late February 2025, completes by late March 2026. How this affects your organization: Who is affected: Admins managing Microsoft Purview Information Protection and custom sensitive information types (SITs). What will happen: By default, the feature will be available to all tenants. Admins will see a new option to simulate a custom classifier before publishing. Simulation is optional — admins can choose to simulate or publish directly. Classifiers published without simulation will still be monitored for performance and flagged if unhealthy. Classifier health insights will be available in the Microsoft Purview compliance portal, helping admins identify and remediate inefficient classifiers. Inefficient classifiers may be automatically disabled to maintain system performance. What you can do to prepare: Admins can begin using Simulation Mode once available; no onboarding or training is required. Once the feature is available: Review classifier health insights in the compliance portal. Monitor any SITs flagged as unhealthy and adjust logic as needed. Consider simulating classifiers before publishing to reduce risk of false positives or performance issues. Compliance considerations: Question Explanation Does the change alter how existing customer data is processed, stored, or accessed? Classifiers will be simulated on production data, but not published, […]

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