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An Alternate Internal Part Number (Alternate IPN) is a part number approved for a more specific application than a standard IPN. Alternate IPNs are parts or components with the same characteristics as the original IPN but have a different part number. Alternate IPNs can be substituted when the original part is out of stock or otherwise unavailable. An Alternate IPN may be exactly equivalent to the original IPN but from a different manufacturer, or it could be a similar part from the same manufacturer that will work if the original part is unavailable. Having Alternate IPNs helps keep costs and lead times down.

Variants

A part number variant is a variation of an Internal Part Number used to represent different sizes, colors, or other attributes of the same configurable assembly.

Manufacturer Part Numbers

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A Manufacturer Part Number (MPN) is a unique identifier that provides a standard way to reference parts; it identifies a part as belonging to and originating from a specific manufacturer. Each part a manufacturer makes has a unique Manufacturer Part Number to differentiate it from similar parts—and in some cases, even counterfeit parts. MPNs also help manufacturers and sellers identify and manage stock levels and assures buyers that they are getting the right part. 

Vendor Part Numbers

A Vendor Part Number (VPN) is a part number used by a vendor from whom you may buy parts or components to manufacture your products or assemblies. 

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