---
sourceDocument: Australia ServiceNow AI Platform Capabilities
sourceDocumentLink: https://www.servicenow.com/docs/r/australia/servicenow-platform

 Release :

    - australia

ft:locale :

    - en-US

ft:publication_title :

    - Australia ServiceNow AI Platform Capabilities

ft:clusterId :

    - platcap

bundleId :

    - platcap

workflow :

    - Platform


---

# About principal classes

# Principal classes in CMDB success advisor {#ariaid-title1}

Release version: Australia  
Updated September 28, 2026  
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## Summary of Principal classes in CMDB success advisor

Principal classes are configuration item (CI) classes designated as business-critical within your CMDB.
In CMDB Success Advisor, these classes define the scope of the Data Foundations advisor, helping to focus and maintain the accuracy of your CMDB by prioritizing the most important CI classes for your organization.
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## Principal Class Selection and Management

CMDB Success Advisor analyzes your instance's historical data---such as incidents, problems, and changes---to recommend principal classes ranked by relevance. You select from a grouped, recommended list during the Data Foundations advisor scope setup, and these classes are automatically set as principal when saved.

Continuous data quality monitoring is available through the Data Foundations advisor dashboard, enabling ongoing management of principal classes.

## Customization and System Properties

Administrators with the **sncmdbadmin** role can customize principal class recommendations using system properties that control factors such as:

* Duration of task history scanned for recommendations (default 180 days)
* Maximum number of recommended classes shown
* Inclusion of custom CI classes not listed by default
* Provision for predefined recommendation criteria on instances lacking task history

These properties enable fine-tuning of the recommendation scope and relevance according to your environment.

## Synchronization and Scope Accuracy

The Data Foundations advisor maintains its own record of principal classes in scope, which does not automatically update when changes are made outside the advisor (e.g., via CI Class Manager or direct instance updates).

When principal classes are modified outside the advisor:

* Newly designated principal classes are not automatically added to the advisor scope.
* Classes removed as principal externally remain in the advisor scope until manually removed.

An out-of-sync notification appears on the advisor dashboard if discrepancies exist. To ensure accurate scope and smooth operation, it is recommended to manage principal classes directly within CMDB Success Advisor.

## Impact on CI Filtering and Platform Behavior

When configuring Data Foundations or Hardware Asset Management (HAM) advisor scopes, CMDB Success Advisor sets selected CI classes as principal in the platform's CMDB Class Information table. The HAM scope applies first if both products are used.

Principal classes influence ServiceNow AI Platform behavior by filtering Configuration Item fields on task records to show only CIs belonging to principal classes. This enhances task relevance and data quality.

If task forms display limited CI options due to filtering, adjust the **com.snc.task.principalclassfilter** system property to exclude affected task types rather than unchecking the Principal Class box on CI classes, preserving advisor functionality.

## Practical Considerations for ServiceNow Customers

* Use CMDB Success Advisor to identify and maintain your business-critical CI classes, ensuring your CMDB scope is focused and relevant.
* Manage principal classes within the Data Foundations advisor dashboard to maintain synchronization and avoid scope discrepancies.
* Leverage system properties to customize recommendations to your organization's needs.
* Understand that principal classes affect task form CI filtering, and adjust system properties thoughtfully to resolve any filtering issues without disrupting CMDB Success Advisor operations.  
Principal classes are CI classes that your organization treats as business-critical. In CMDB success advisor, the CI classes you select define the Data Foundations advisor scope.

Selecting the right principal classes keeps your CMDB focused and accurate.

## Principal class selection {#cmdb-sa-principal-class__section_rdj_rxd_k3c}

CMDB success advisor processes your instance's history and ranks CI classes by relevance before you set up your Data Foundations advisor scope.

For information about selecting principal classes, see the [Guidance on designating principal classes in the CMDB \[KB2707240\]](https://support.servicenow.com/kb_view.do?sysparm_article=KB2707240) article in the Now Support Knowledge Base.

You can manage the most important CI classes with CMDB success advisor by:

* Selecting CI classes from the grouped, recommended list in the Data Foundations scope setup. Classes are set as principal automatically when you save.
* Using intelligent recommendations based on a weighted score of your instance's past incident, problem, and change (IPC) activity, CI count, and CI class category. For more information, see [CI class recommendations](https://www.servicenow.com/docs/5Ak4WceM0A2w9Wcs9DLXTw "CMDB success advisor analyzes your instance's CI and task data to recommend which CI classes should be in your Data Foundations scope.").
* Monitoring data quality continuously through the Data Foundations advisor dashboard.
{#cmdb-sa-principal-class__ul_lmn_5b2_k3c}

## Principal class tracking in CMDB success advisor {#cmdb-sa-principal-class__section_pky_rf2_k3c}

Use the following system properties to customize how CMDB success advisor recommends and manages principal classes. With the sn_cmdb_admin role, you can adjust these properties to control the scope and quality of principal class recommendations.
{#cmdb-sa-principal-class__table_qky_rf2_k3c__entry__2}

| Property | Purpose |
|-|-|
| sn_cmdb_advisor.principal_class_suggestion_period | Number of days of task history CMDB success advisor scans when generating class recommendations. Default value: 180 days |
| sn_cmdb_advisor.suggested_principal_classes_limit | Maximum number of recommendations shown in the Recommended group. Default value: 20 |
| sn_cmdb_advisor.principal_class_others | Comma-separated list of custom CI classes to include in the Others group of the Manage principal classes selection. Note: Use this property when the custom CI classes aren't available in the predefined Data Foundations advisor scope setup list. |
| sn_cmdb_advisor.principal_class_recommendation_criteria | Keyword value (`PREDEFINED`) that displays a standard set of commonly managed CI classes as recommendations on instances with no prior task activity. This property does not exist by default and must be created manually. |
[Table 1. System properties in CMDB success advisor for principal classes]

{#cmdb-sa-principal-class__table_qky_rf2_k3c}

The sn_cmdb_advisor.principal_class_recommendation_criteria property is optional. Create it on instances with no prior task activity where task-based recommendations produce no results. Setting the value to
`PREDEFINED` displays a standard set of commonly managed CI classes as recommendations. For instructions, see [Create the principal class recommendation criteria property](https://www.servicenow.com/docs/zFGKfppIEkC78tH4lALA4A "Create the sn_cmdb_advisor.principal_class_recommendation_criteria system property to filter which CI classes CMDB success advisor considers when generating principal class recommendations for the Data Foundations advisor.").

## Principal class synchronization {#cmdb-sa-principal-class__section_yr5_qll_m3c}

The Data Foundations advisor stores its own record of which CI classes are in scope. The advisor does not automatically reflect changes to principal class designations made through CI Class Manager or made directly in
the instance. A comparison runs when you open the dashboard to identify any discrepancies.

The following behaviors apply when principal class changes are made outside the advisor:

* When you set a class as principal outside CMDB success advisor, the class is set as principal on the instance. This applies after the Data Foundations advisor dashboard scope is configured. However, it isn't automatically added to the Data Foundations advisor dashboard scope.
* When you remove the principal designation from a class outside the advisor, the class remains in the Data Foundations advisor dashboard scope until you remove it manually.

{#cmdb-sa-principal-class__ul_yqb_qml_m3c}

To keep the Data Foundations advisor dashboard scope accurate, make all principal class updates directly in CMDB success advisor by selecting Manage principal classes on the Data Foundations advisor dashboard. For more information, see [Managing Data Foundations advisor scope in CMDB success advisor](https://www.servicenow.com/docs/T9VARzdrPGUp3HrryktlHw "After the Data Foundations advisor dashboard is configured, you can update the principal class scope to keep it aligned with your goals, and resolve discrepancies when classes are changed outside the advisor.").

If other tools or processes change principal classes outside the advisor, an out-of-sync notification appears when you open the Data Foundations advisor dashboard. For more information, see [Principal class sync in Data Foundations advisor](https://www.servicenow.com/docs/82sDnvJOiWKIBVgHoGMRCQ "When other tools or processes add or remove principal classes outside the advisor scope, the Data Foundations advisor displays a notification prompting you to review and update the scope.").

## CI filtering based on principal classes {#cmdb-sa-principal-class__section_c4l_3py_rjc}

When you configure a Data Foundations or HAM advisor scope through auto-setup or manual setup, CMDB success advisor automatically sets the selected CI classes as principal class in the platform CMDB Class Information \[cmdb_class_info\] table.

If both products are configured on the same instance, HAM scope is applied first, followed by Data Foundations. If principal classes already exist on the instance, CMDB success advisor preserves those principal classes and adds to the existing selection.

Principal classes affect ServiceNow AI Platform behavior beyond CMDB success advisor. After a CI class is set as principal, the platform can filter the Configuration Item field on task records so that only CIs that belong to principal classes are
available.  
Note:  
CMDB success advisor requires principal classes to define advisor scope and function correctly. The system property com.snc.task.principal_class_filter determines which task types apply the Configuration Item filter. If only a limited set of CIs are seen on task forms such as incidents or change requests, remove the affected task table from the com.snc.task.principal_class_filter system property. Don't clear the Principal Class check box on CI classes in the CMDB Class Information \[cmdb_class_info\] table to resolve task form filtering issues. This change disables principal class filtering for that task type while allowing CMDB success advisor to continue operating correctly. For more information, see [Principal Class](https://www.servicenow.com/docs/ENE4G2KZHXZ4qUyd2nyztg "A Principal Class is a designation for those CMDB classes that are most critical for foundational data health and governance in the organization. Those classes are then prioritized for tracking, health, certification, lifecycle management, and class list views.").