The element <optionalPart> provides one or several optional parts that are equivalent alternatives to the defined part. It represents a choice between parts that are exactly the same (fit, form and function) but have different manufacturers (this often occurs for standard parts).The installation of an optional part does not change the product configuration.The optional part can be identified by:− using the part number and manufacturer code (allowing then to refer to the part common information repository data module, if it is implemented) or− using the reference to the catalog sequence number where the part is described