• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other Pie Elite all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Jeanne Boyarsky
  • Ron McLeod
  • Paul Clapham
  • Liutauras Vilda
Sheriffs:
  • paul wheaton
  • Rob Spoor
  • Devaka Cooray
Saloon Keepers:
  • Stephan van Hulst
  • Tim Holloway
  • Carey Brown
  • Frits Walraven
  • Tim Moores
Bartenders:
  • Mikalai Zaikin

When "extend" stereotype in UML can be used?

 
Greenhorn
Posts: 4
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I know when there is some alternatives in the way of one usecase , another usecase can extend it.But I don't know exactly how to write scenario for the second usecase.For example , suppose you want to draw usecase diagram of book deposit in a library , for the usecase of lending book there is an alternative way when the book is borrowed and the action of lending would be rejected.I don't know how to write scenario for the usecase extending the deposit usecase.
 
Greenhorn
Posts: 8
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Generalization and extends should be used for cases which are not just simple alternatives. Only if the alternative is not simple and makes the main use case very complex if incorporated in it, should we think of a generalization relationship. For extends, extension points need to be provided in the main use case and the extending use case can only extend it at these points. Extends is a more formal kind of a generalization.
Regards
majid
 
Consider Paul's rocket mass heater.
reply
    Bookmark Topic Watch Topic
  • New Topic