CI Lookup rules are not working

[Rashmi Bansal]

I have created a lookup rule to search the cmdb_ci_service_auto table using the Business Service ID and populate the corresponding CI in the Configuration Item field of the discovered application. However, the lookup is not working as expected; instead of populating the CI, it is populating the Product Model. The instance is configured with CSDM 4.0. Could you please help identify what might be causing this behavior? or is this a expected behavior?

[Tanushree Maiti]

Hi @Rashmi Bansal 

• Ensure your lookup rule has explicit Table and Class conditions configured so it queries the Application Service tables rather than defaulting to cmdb_hardware_product_model
• If you are using a scripted lookup rule, debug your script logic to confirm your GlideRecord queries are targeting sys_id of the CI itself.
• Ensure you are not inadvertently mapping into the model_id field or a field referencing cmdb_model
• Review any Business Rules or Client Scripts running on your discovered application table.

[Bhargavi Patel]

Hi  @Rashmi Bansal 

This is not expected behavior if your lookup rule is configured correctly.

Check the following:

• Verify the lookup rule target field is Configuration Item (cmdb_ci) and not Product Model.
• Confirm the Business Service ID maps to a valid record in cmdb_ci_service_auto.
• Review any Transform Maps, Business Rules, or Data Manager rules that may be overriding the CI and populating the Product Model instead.
• Ensure your CSDM 4.0 mapping aligns with the discovery/reconciliation process.

If all of the above is correct, enable debugging for the lookup rule or review the Discovery logs to identify what is updating the Product Model.

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[Mohammad3]

Hi @Rashmi Bansal 

Based on the behavior you've described, this is not expected with CSDM 4.0. CSDM itself doesn't change how Lookup Rules populate fields.

I would start by verifying that the Lookup Rule is configured to return the Configuration Item reference and not another field. If the rule is correct, the next place to look is for any custom Business Rules, Flows, Transform Maps, or other server-side logic that may be updating the record after the lookup executes.

I would also recommend reproducing the behavior in a PDI or sub-production instance. If it works as expected there, it's likely an instance-specific customization. If the issue can be reproduced on an out-of-the-box instance, I'd suggest opening a case with ServiceNow Support, as this would not be considered expected platform behavior.

[Rashmi Bansal]

What I have observed is ServiceNow expects data to come to Scanned Applications first, only then CI's will be lookup up for the target table and target field and then lookup rule will work. But this seems to be products limitation since I have the direct sys_id of the CI available, then I can map that to the CI field in discovered applications directly instead of Lookup rules to work via Scanned applications.

What do you think?