Abstract:
Stereotypes are a powerful and potentially expressive extension
mechanism in the Unified Modeling Language (UML). However, it
seems that stereotypes are difficult to handle because using stereotypes
needs an understanding of the UML metamodel and, in particular, an understanding
of OCL constraints. Stereotypes are often applied in a wrong
or at least sloppy way without proper declaration. There are also differences
between the various versions of UML with respect to subtle details
in the stereotype part. A graphical syntax for stereotypes including examples
has been introduced only late in UML 1.4. Other difficulties are
that constraints are used in the stereotype context in two completely
different ways and that no full support of stereotypes is yet offered by
tools. The paper points out these difficulties in detail, analyses the UML
metamodel part dealing with stereotypes, and makes various suggestions
for improving the definition and use of stereotypes.
