1. Ingest the source files. Vendor CSVs, channel exports, retailer remittance sheets, anything that carries SKUs in a foreign format.
2. Pull the master list. The internal SKU table from NetSuite, Fulfil, or whichever ERP holds the canonical version.
3. Normalize the variant codes. Trim whitespace, fix casing, strip retailer prefixes, expand abbreviated codes. Apply your house format.
4. Match against the master. Exact match first, then fuzzy match on description and UPC for the ones that need help.
5. Flag the unmatched. SKUs that did not resolve land in a review queue with the candidate matches the flow considered.
6. Output the mapping table. Vendor SKU, channel SKU, retailer SKU, internal SKU, all in one place. Plus a clean exception list for the master data team.