ItemVersions (DocumentVersions and PartVersions) are company specific keys / identifiers for a part (component) or a piece of information. However, this also means that the same part, or piece of information, can have different identifiers depending on the context. The keys refer semantically to the same element or in other words, they are equivalent. The class ItemEquivalence enables the description of such equivalence relationships between two or more ItemVersions. A standard use case is to relate PartVersions defined in the context of different companies for part number translation (e.g. OEM part number -> Tier 1 part number -> component supplier part number).
Note: That equivalent ItemVersions refer to the semantically same element does not mean, that the information associated with the ItemVersions has to be identical. For example, the same component might have different approved operating conditions depending on the company scope, which results in differing technical attributes.