On the Semantics of the Extend Relationship in Use Case Models: Open-Closed Principle or Clairvoyance?

  • Miguel A. Laguna
  • José M. Marqués
  • Yania Crespo
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6051)


A use case is a description of the interactions of a system with the actors that use it. The Achilles’ heel of use cases is the unclear UML semantics, in particular the definition of the extend relationship. This article is an attempt to clarify the semantics of the extension mechanism. In particular, we advocate for the application of the open-closed principle, adding modification details in the extending use case, instead of in the base case. A revision of the UML standard would be impractical, but a disciplined reinterpretation of the extend and extension point concepts could represent a great improvement. Textual and graphical approaches (based in the UML Behavior meta-model) are considered. Using these recommendations, the base use cases can be independently described, while the extending use cases will be self-contained.


use case extend relationship extension point UML meta-model 


  1. 1.
    Araujo, J., Whittle, J., Kim, D.: Modeling and Composing Scenario-Based Requirements with Aspects. In: Proceedings of the 12th IEEE international Requirements Engineering Conference (2004)Google Scholar
  2. 2.
    Berard, E.V.: Be Careful with Use Cases. Technical report. The Object Agency, Inc. (1995)Google Scholar
  3. 3.
    Braganca, A., Machado, R.J.: Extending UML 2.0 Metamodel for Complementary Usages of the «extend» Relationship within Use Case Variability Specification. In: Proceedings of the 10th international on Software Product Line Conference, pp. 123–130. IEEE Computer Society, Washington (2006)CrossRefGoogle Scholar
  4. 4.
    Cockburn, A.: Writing Effective Use Cases. Addison-Wesley Professional, Reading (2000)Google Scholar
  5. 5.
    Constantine, L., Lockwood, L.: Software for Use. Addison-Wesley, Reading (1999)Google Scholar
  6. 6.
    France, R., Kim, D., Ghosh, S., Song, E.: A UML Based Pattern Specification Technique. IEEE Transactions on Software Engineering 30(3), 193–206 (2004)CrossRefGoogle Scholar
  7. 7.
    Génova, G., Llorens, J., Metz, P., Prieto-Díaz, R., Astudillo, H.: Open Issues in Industrial Use Case Modeling. In: Jardim Nunes, N., Selic, B., Rodrigues da Silva, A., Toval Alvarez, A. (eds.) UML Satellite Activities 2004. LNCS, vol. 3297, pp. 52–61. Springer, Heidelberg (2005)Google Scholar
  8. 8.
    Génova, G., Llorens, J.: The Emperor’s New Use Case. Journal of Object Technology 4(6), 81–94 (2005); Special Issue: Use Case Modeling at UML 2004Google Scholar
  9. 9.
    Genilloud, G., William, F.: Use Case Concepts from an RM-ODP Perspective. Journal of Object Technology 4(6), 95–107 (2005); Special Issue: Use Case Modeling at UML 2004Google Scholar
  10. 10.
    Isoda, S.: A Critique of UML’s Definition of the Use-Case Class. In: Stevens, P., Whittle, J., Booch, G. (eds.) UML 2003. LNCS, vol. 2863, pp. 280–294. Springer, Heidelberg (2003)Google Scholar
  11. 11.
    Jacobson, I.: Use Cases and Aspects—Working Seamlessly Together. Journal of Object Technology (2003),
  12. 12.
    Jacobson, I., Booch, G., Rumbaugh, J.: The Unified Software Development Process. Addison-Wesley, Reading (1999)Google Scholar
  13. 13.
    Jacobson, I., Christerson, M., Jonsson, P., Overgaard, G.: Object-Oriented Software Engineering, A Use Case Driven Approach. Addison-Wesley, Reading (1994)Google Scholar
  14. 14.
    Jacobson, I., Griss, M., Jonsson, P.: Software Reuse. In: Architecture, Process and Organization for Business Success, ACM Press/Addison Wesley Longman (1997)Google Scholar
  15. 15.
    Larman, C.: Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and the Unified Process, 3rd edn. Addison Wesley, Reading (2004)Google Scholar
  16. 16.
    Meyer, B.: Object Oriented Software Construction. Prentice-Hall, Englewood Cliffs (1988)Google Scholar
  17. 17.
    Metz, P., O’Brien, J., Weber, W.: Specifying Use Case Interaction: Clarifying Extension Points and Rejoin Points. Journal of Object Technology 3, 87–102 (2004)Google Scholar
  18. 18.
    Mylopoulos, J., Bernstein, P.A., Wong, H.K.: A language facility for designing database-intensive applications. ACM Trans. Database Syst. 5(2), 185–207 (1980)CrossRefGoogle Scholar
  19. 19.
    OMG, Unified Modeling Language: Superstructure, version 2.1.2. formal doc. 2007-11-01. 2007 (2007)Google Scholar
  20. 20.
    Rational Software Corporation Unified Modelling Language Version 1.1 (1997)Google Scholar
  21. 21.
    Rosenberg, D., Scott, K.: Applying Use Case Driven Object Modeling with UML: A Practical Approach. Addison Wesley, Reading (1999)Google Scholar
  22. 22.
    Rumbaugh, J., Blaha, M., Premerlani, W., Eddy, F., Lorensen, W.: Object-Oriented Modeling and Design. Prentice Hall, Englewood Cliffs (1991)Google Scholar
  23. 23.
    Rumbaugh, J., Jacobson, I., Booch, G.: The Unified Modeling Language Reference Manual, 2nd edn. Addison-Wesley Professional, Reading (2004)Google Scholar
  24. 24.
    Simons, A.J.H.: Use Cases Considered Harmful. In: 29th Conf. Tech. Obj-Oriented Prog. Lang. and Sys. (TOOLS-29 Europe), pp. 194–203. IEEE Computer Society, Los Alamitos (1999)Google Scholar
  25. 25.
    Somé, S.S., Anthonysamy, P.: An approach for aspect-oriented use case modeling. In: Proceedings of the 13th international Workshop on Software Architectures and Mobility, pp. 27–34 (2008)Google Scholar
  26. 26.
    Sousa, G., Soares, S., Borba, P., Castro, J.: Separation of crosscutting concerns from requirements to design: Adapting the use case driven approach. In: Proceedings of the Early Aspect Workshop at AOSD, pp. 93–102 (2004)Google Scholar
  27. 27.
    van den Berg, K.G., Simons, A.J.H.: Control flow semantics of use cases in UML. Information and Software Technology 41(10), 651–659 (1999)CrossRefGoogle Scholar
  28. 28.
    Whittle, J.: Precise specification of use case scenarios. In: Dwyer, M.B., Lopes, A. (eds.) FASE 2007. LNCS, vol. 4422, pp. 170–184. Springer, Heidelberg (2007)CrossRefGoogle Scholar
  29. 29.
    Williams, C., Kaplan, M., Klinger, T., Paradkar, A.: Toward Engineered, Useful Use Cases. Journal of Object Technology 4(6), 45–57 (2005); Special Issue: Use Case Modeling at UML 2004Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Miguel A. Laguna
    • 1
  • José M. Marqués
    • 1
  • Yania Crespo
    • 1
  1. 1.Department of Computer ScienceUniversity of ValladolidValladolid

Personalised recommendations