Six degrees of UML problems
According to Gartner Inc. analyst Chris Duggan, there are six main areas where
UML has problems.
1. Coupling to the business process. "Our client base wants something
that lets them talk to the business user in his language. If that's the case,
UML notation and object modeling seem to be a pretty draconian approach because
they begin with use cases; and, sometimes, use cases arenÕt the most
appropriate way of starting off," Duggan said.
2. Coupling to components. "The component architecture is one where
even proponents of UML feel pretty strongly that there are a variety of ways
you could do components in UML at the 1x level, none of which was particularly
strong," he noted.
3. Round-tripping between code and class is very poor in UML. "Generation
requires very specific integration to an IDE and, depending on which side of
that practice you're standing on, you could either say it's a great idea to
simultaneously generate code or it's horrible. But it requires patterns for
development and design," Duggan said.
4. Lack of smooth coupling between modeling notations in UML and the actual
IDE code. "TogetherSoft and Embarcadero built a tight coupling so you
could jump back and forth between modeling notations and the code; that's really
an extension beyond UML," Duggan said.
5. The lack of a physical design. "While UML has logical design
and the object design is at the conceptual level, you don't have UML-related
physical design. You still have a transition to a different design technique,
and you have to go back and forth across this notational boundary, which is
annoying," Duggan said. Rational, with Rose Data Modeler, and Embarcadero
offer solutions for this, he added.
6. Group support. "This one is more implementation than notation
-- UML modeling tools tend to be flat file-based, not repository-based,"
Duggan said. "In practice, Rational Rose led you to lots of problems in
terms of whether you had a current representation of the model or there was
another version somewhere, and versioning of models became a problem."
Richard Adhikari is a widely published high-tech writer based in Silicon Valley. He can be reached via e-mail at firstname.lastname@example.org.