Model the same flow both as part of one use case and as a separate, complete use case of its own.
Characteristics: Rather common. Basic solution.
Keywords: Addition to existing flow, complete subflow, extend, include, reuse, subflow.
Concrete Extension or Inclusion: Extension pattern consists of two use cases and an extend relationship between them. The extension use case is concrete; that is, it may be instantiated on its own as well as extend the base use case. The latter can be either concrete or abstract.
The pattern ...