UMLn

UMLn, short for Unified Modeling Language next, is a proposed extension to the UML family intended to help model complex, dynamic, and distributed software and systems. It maintains core UML concepts while expanding notation, semantics, and tooling to address runtime reconfiguration, adaptive behavior, and cross-cutting concerns such as non-functional requirements. UMLn is described in academic and professional discussions as a way to bridge modeling at design time with behavior observed at run time.

Core ideas include a set of extended diagram types, such as n-activity diagrams, n-sequence diagrams, and n-structure diagrams, which add constructs for dynamic reconfiguration, multi-level layering, and explicit treatment of non-functional properties. The approach emphasizes modular composition, scalable hierarchies, and traceability from requirements to deployment.

Status: Not standardized. There is no official OMG standard for UMLn. Proposals remain largely experimental and are discussed in academic papers and conference tutorials. Tool support is limited, with only experimental plugins or research prototypes. In practice, UMLn is generally viewed as a theoretical extension rather than an industry-ready standard.

Impact and reception: In theory, UMLn could improve modeling of self-adaptive and cloud-native systems, complex event processing, and runtime quality assurance. Critics argue that it adds substantial complexity and may fragment existing UML workflows. The balance between expressive power and usability remains a central concern.

See also: UML, SysML, model-driven engineering, software architecture.