Resolve a Legacy Part Number to a Current SKU

A sales rep receives an order referencing part number XY-2040. That number does not appear in the current catalog. It might be a customer’s internal code, a manufacturer’s old number, a supplier’s identifier, or a number from a system the company migrated off five years ago. Somewhere in the catalog data — or in a spreadsheet, a product specialist’s memory, or a manufacturer’s archive — there is a path from XY-2040 to the part the customer actually needs.

The workflow

1. Normalize the input

   Before looking anything up, clean the part number:

   • Strip leading and trailing whitespace
   • Remove or normalize hyphens, slashes and dots (depending on your convention)
   • Uppercase (unless the manufacturer’s numbering is case-sensitive, which is rare)
   • Remove leading zeros if your system does not use them
   • Check for common transcription errors: O vs 0, I vs 1, l vs 1

   The goal is to match the format used in your cross-reference tables. A lookup that fails because of a stray space or a missing hyphen is the most common false negative.

2. Look up in cross-reference tables

   Search your crosswalk / cross-reference tables for the normalized number. Check:

   • Customer-to-internal mappings (the number may be the customer’s internal code)
   • Supplier-to-internal mappings (the number may be the supplier’s code)
   • OEM-to-aftermarket mappings
   • Old-to-new mappings

   If found, note the internal SKU or MPN it maps to, and proceed to step 3 with that number.

3. Check supersession records

   Look up the number (or the internal SKU from step 2) in the supersession table. If it has an outgoing REPLACED_BY edge:

   • Follow the chain to the terminal node — the part with no further outgoing REPLACED_BY edge
   • Check that the terminal node’s status is “active” (not itself discontinued)
   • Note any quantity-ratio changes along the chain
   • Note any splits (one old part → multiple new parts)

   If the chain is broken (the terminal node is also discontinued with no successor), flag it. The customer needs to know there is no current replacement, not just silence.

4. If not found: check external sources

   If the number is not in your cross-reference or supersession tables:

   • Search the manufacturer’s website or online parts catalog for the number
   • Check the manufacturer’s supersession bulletins or product-change notices
   • Search supplier portals and third-party cross-reference databases
   • Ask a product specialist who may know the product line’s history
   • Check old catalogs, price lists, or archived ERP data for historical records

   If any of these yield a mapping, add it to your cross-reference or supersession table with the source recorded.

5. Confirm the result

   Before telling the customer or placing an order, verify:

   • Do the successor’s key specifications match what the legacy part was used for? (Dimensions, ratings, material)
   • If there was a quantity-ratio change, does the order quantity need adjusting?
   • If there was a split, does the customer need all of the successor parts?
   • Is the successor in stock and orderable?

   A supersession record says the manufacturer replaced A with B. It does not guarantee that B is the right part for the customer’s specific application — especially if the customer was using A in a non-standard way.

6. Record the resolution

   Whether or not you found a match, record the outcome:

   • Found: add or update the cross-reference/supersession record with the source, date and confidence
   • Not found: record the lookup attempt so the next person who encounters the same number does not repeat the search from scratch
   • Ambiguous: record the candidate matches and the open question for a product specialist to resolve

Decision tree for common cases

Common pitfalls

• Skipping normalization — a failed lookup due to formatting wastes the product specialist’s time.
• Stopping at the first hop in a supersession chain — the immediate successor may itself be discontinued.
• Not checking quantity ratios — a pack-size change means the order quantity needs adjusting.
• Treating a cross-reference as a supersession — a supplier-to-internal mapping is not the same as a manufacturer’s REPLACED_BY declaration.
• Not recording the resolution — the next person who encounters the same legacy number starts from scratch.

Where Claro fits

Claro resolves legacy part numbers against the Product Identity & Evidence Graph. When a legacy number arrives — from a customer order, an old BOM, or a migration file — Claro normalizes it, searches across all crosswalk types, follows supersession chains to the current active part, and presents the result with the evidence behind each step. Unresolved numbers surface in an exception queue for the catalog team.

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