How to fix issue with duplicate CI's

[Maajidqureshi5]

How I can fix the issue with SCCM discovery it is creating duplicate  CI's and assests for new laptops

[Sandeep Rajput]

@Maajidqureshi5 Please refer to this excellent knowledge article https://support.servicenow.com/kb?id=kb_article_view&sysparm_article=KB0829103 which covers this topic in detail 

[AparnaSahu]

Hi @Maajidqureshi5 ,

Fixing Existing Duplicate Hardware Models

1. Review Normalization Candidates

Navigate to Product Catalog → Hardware Models → Normalization Candidates.

• Identify duplicate or similar hardware models (for example, the same device with slight variations in the model name or manufacturer).

• Select the correct model and update the related CIs to reference it.

• Retire or deactivate any duplicate models that are no longer required.

2. Complete Manual Model Normalization

If a model is marked as Partially Normalized, it typically indicates that the model information is missing or invalid.

• Update the Hardware Asset Model with the correct manufacturer and model details.

• Ensure it is properly linked to the corresponding cmdb_hardware_product_model record.

3. Configure Model Mapping (Optional)

To improve future imports, create Model Mapping Rules through CI Class Manager. These rules help map incoming model names from discovery sources to the correct hardware model.

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Preventing Future Duplicates

Enable Model Normalization

Enable model normalization by setting the following system property:

glide.cmdb.normalize_models = true

Configure Reconciliation Rules

Navigate to Data Reconciliation → Reconciliation Rules and configure trusted data sources.

For example:

• Give Discovery higher precedence than SCCM for attributes such as Model and Serial Number.

• Ensure the most trusted source is responsible for updating these fields.

Leverage the Identification and Reconciliation Engine (IRE)

Review your Identification Rules for hardware CI classes to ensure they accurately identify existing records.

Where appropriate:

• Include Model as part of the identification criteria.

• Verify that both SCCM and Discovery data are correctly mapped before being processed by the IRE.

Control Automatic Model Creation

If duplicate models continue to be created, consider restricting automatic model creation from SCCM. Instead, route new models through a staging process or approval workflow before adding them to the product catalog.

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Hardware Model Best Practices

• Maintain cmdb_hardware_product_model as the authoritative hardware model catalog.

• Standardize manufacturer names using the cmdb_mfr manufacturer table.

• Regularly review Normalization Candidates to identify and merge duplicate models.

• Designate a single trusted source (such as Discovery or SCCM) to own hardware model information wherever possible.

• Use Model Categories consistently to classify hardware (e.g., desktops, laptops, servers) and improve reporting and data quality.

Thanks,

Aparna