UMLderived

UMLderived is a term used in some UML modeling discussions to denote elements whose values are derived from other elements in the model, rather than stored directly. It is not an official UML standard term, but it is used to distinguish computed data from persistent data within diagrams and specifications.

Notation in UML for derived features typically uses two forms. A feature is marked as derived by prefixing its name with a slash, as in /fullName. Alternatively, a {derived} constraint may be attached to the feature to indicate its derived status. This notation helps modelers convey that the value is not stored but calculated from other attributes or relationships.

Examples include a Person class with firstName and lastName attributes and a derived attribute fullName, computed as firstName + " " + lastName. Another example is a derived association representing the transitive closure of a parent relation, where the relationship is not stored explicitly but inferred from existing links.

Semantics and usage considerations: Derived features are typically read-only and re-evaluated when base elements change. In practice, their implementation may be a computed property or a function, often specified with an expression or OCL rule. While derived features can simplify models and reflect business logic, they can introduce performance concerns and potential inconsistencies if the derivation depends on mutable data or forms cycles.

Relationship to standards: The concept aligns with UML’s established notions of derived properties and constraints, though “UMLderived” as a label is informal and tool- or project-specific rather than an official UML term.