When is a New Part Number needed

When a product changes, is a new part number required?

A few questions need to be answered about the changed parts. If they are revisions to the existing part, would you ever make the product the old way again? A BOM can be revised and the old BOM can be stored, providing a history of how the product was made in the past AND the option to produce the product with the old BOM if needed.

The preferred treatment of changes is to create a new part number. The rule that is usually followed is called Form, Fit, Function. If any of those three change, a new part number is called for. If the "new" part is a perfect replacement for the old part number, it can be recorded as a revision of the existing product structure. If, however, the new part has changed features, new features, is used for a different purpose, or is not interchangable with the existing part, a new part number is called for.