Required Fields for CMDB Health

[pramodkumar]

Hi All,

I am looking to make the Serial Number attribute mandatory on the cmdb_ci_computer table. However, the field is inherited from the CMDB Base (cmdb_ci) table. How can I enforce it as required only for the cmdb_ci_computer class? Also, how is this related to CMDB Completeness? I was unable to make the serial_number field mandatory on cmdb_ci_computer through CI Class Manager.

Thanks!

[21121A3359]

Hai @pramodkumar 

The Serial Number field is inherited from the CMDB Base table (cmdb_ci), so it cannot be made mandatory directly on the cmdb_ci_computer table via CI Class Manager. That’s why you’re unable to enforce it there.

However, you have two supported ways to handle this requirement:

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Option 1: Use a Data Policy (Recommended)

A Data Policy allows you to make a field mandatory only for a specific CI class, without impacting other child classes.

Steps:

1. Navigate to System Policy → Data Policies
2. Create a new Data Policy:
   • Table: cmdb_ci_computer
   • Active: true
3. Under Data Policy Rules:
   • Field: serial_number
   • Mandatory: true
4. Save the record

This enforces the Serial Number as mandatory both in UI and API for cmdb_ci_computer only.

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Option 2: Use a UI Policy (UI-only)

If you only need this enforcement in the UI, you can use a UI Policy.

Note:
 UI Policies do not apply to imports, integrations, or APIs.

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How This Relates to CMDB Completeness

CMDB Completeness is calculated based on Identification Rules and Completeness Rules, not mandatory fields.

• Making a field mandatory does not automatically improve CMDB Completeness
• To include Serial Number in completeness:
  • Add it as a required attribute in CMDB Completeness Rules
  • Or include it in Identification Rules, if applicable

[GaganR021259991]

Hi @pramodkumar 
To satisfy this condition where you want the Serial Number Field mandatory only on the cmdb_ci_computer table You can create a Data Policy
Please follow the below steps:

1. Navigate to System Policy → Data Policies
   

2. Create a new Data Policy:

   • Table: cmdb_ci_computer
     
   • save the form 
   • Then scroll down to find Data Policy Rules in the related list.
3. Create a new Data Policy Rule:
   • Field: serial_number
   • Mandatory: true
     

   • update the form.

4. Please mark this response as Helpful & Accept it as solution if it assisted you with your question.
   Regards,
   Gagan R Prasad.

[GaganR021259991]

Hi @pramodkumar 
Forgot to Answer the question how is this related to CMDB Completeness?

CMDB Health measures data quality across three pillars — Completeness, Compliance, and Correctness. Completeness specifically asks: "Are the required attributes populated for this CI class?"

Serial number is typically included as a tracked completeness attribute for cmdb_ci_computer. Even if you enforce it as mandatory on the form, that only prevents future bad data — it does nothing for CIs already in the CMDB with a blank serial number. This is where Completeness Rules come in.

Completeness Rules defines which fields must be populated for a CI to be considered "complete." CIs missing serial_number will be flagged and pull down the completeness score on your CMDB Health Dashboard.
Please refer below documents for additional details
https://www.servicenow.com/community/cmdb-forum/cmdb-health-dashboard-completeness-compliance-amp-co...

https://www.servicenow.com/community/itsm-articles/understanding-cmdb-health/ta-p/2307033

[Nishant8]

Hello @pramodkumar, I'm not sure about the underlying business requirement, but applying this logic means many of your CIs might fail to create if they lack a serial number. Instead, you can create a Completeness metric as follows

CI Class Manager -> Computer Class -> Expand Health on the left menu and click Completeness -> Add serial_number to the Selected fields list

as a result if a CI is discovered or created without a serial number, it flags a completeness failure.

Technically, you can mark Serial Number mandatory as well - Go to Hardware Class ( parent of Computer ) and open the Attributes -> Derived -> Serial number, and create new Dictionary Overrides by selecting the Computer class and mark it mandator as below:

Regards,

Nishant