Vocabularies and their associated reference data sets are often more than lists of preferred terms and their synonyms. They may also include hierarchical relationships between the terms. These relationships may be general-to-specific classifications (―is a kind of‖ relationships) or whole-part assemblies (―is a part of‖ relationships). There may also be non-hierarchical relationships between terms that are worth identifying.
Affiliation management is the establishment and maintenance of relationships between master data records. Examples include ownership affiliations (such as Company X is a subsidiary of Company Y, a parent-child relationship) or other associations (such as Person XYZ works at Company X). Managing hierarchies specifically within a business intelligence environment is sometimes called dimension hierarchy management.