Duplicate hardware models in HAM: Discovery keeps recreating deleted models

[PushpalD]

Hi Community,

We are working on Hardware Asset Management (HAM) configuration and have identified two records in cmdb_hardware_product_model that represent the same physical model. Model A and Model B have the same manufacturer and effectively the same product name, but they were created separately (for example, one via Discovery and one manually or through an import). Effectively, one is a duplicate of the other.

Both models currently have assets (alm_hardware) and CIs (cmdb_ci_*) linked to them, so we cannot simply delete one without understanding the downstream impact. We also found that even when we delete the duplicate model, Discovery recreates it on the next run.

What we would like to understand:

1. Model consolidation: What is the recommended approach to merge or consolidate duplicates? Should we pick one as the “golden” record and retire the other (inactive or obsolete), or is there a supported way to merge them?
2. Assets: Should the assets linked to the duplicate model be re-pointed to the surviving model by updating the model field on alm_hardware? Are there any side effects on asset lifecycle, stockrooms, contracts, or financial data?
3. CIs: Since the model on the CI is synchronized with the asset, will updating the asset model automatically update model_id on the linked CI, or do we need to update the CI separately? We are also concerned that Discovery or IRE may re-derive the model from raw device data on the next run and revert the CI to the duplicate model.
4. Discovery recreating the deleted model: After we delete the duplicate, Discovery brings it back. What is the root cause and the permanent fix? Is it a mismatch between the discovered manufacturer/model strings and our golden model (or a duplicate manufacturer record such as “Dell” vs “Dell Inc.”)? Does the golden model need to exactly match the value Discovery reports? Is retiring the duplicate (inactive/obsolete) preferable to deleting it so that Discovery finds a match instead of creating a new record?
5. Hardware Model Normalization: Does normalization help in this scenario? Our understanding is that it only populates the normalized manufacturer and model fields and does not automatically consolidate child assets or CIs. Can it be used to stop Discovery (or other sources such as import sets or Service Graph connectors) from creating variant models going forward?
6. Prevention: What else can be done to avoid duplicates in the future (discovery source configuration, model matching rules, import set transform checks, manufacturer cleanup)?
7. Best practice sequence: Is there a recommended order of operations (for example, consolidate manufacturers, align the golden model with the discovered values, re-point assets, confirm CIs, run Discovery on a sample, then retire the duplicate), along with any audit or rollback considerations?

Environment details:

• ServiceNow release: Xanadu
• Plugins: Hardware Asset Management, HAM Pro, CMDB, Discovery

Any guidance, documentation links, or real-world experience would be greatly appreciated.

Thank you!