Dynamic Behaviour in UML Models: Semantic
Questions
Aims and Scope
Although many years of practical experience went into the design of the
UML, the lack of precise semantics still stands in the way of effective
application.
The modelling of complex systems requires techniques that allow us
to manage complexity as well as techniques that allow early detection
of errors in behaviour models.
UML well supports the principle of separation of views that is an effective
means of controlling complexity.
However, UML does not support so well the formality and
rigour needed to early detect errors in requirements and design.
Developing
a precise, complete, and understandable semantics for the UML
that enables practical, tool-supported and rigorous analysis of UML models
can enhance its applicability to the modelling of complex systems. A formal
analysis of the semantic foundations of the UML notations can also lead
to more precise and complete natural language descriptions of the notations
in the UML standard. In addition, the insights provided by a well-defined UML
semantics can help modelers choose appropriately among a variety of modelling
constructs.
These observations are particularly relevant when we consider the dynamic
behaviour of the UML models:
-
UML offers many different notations to represent dynamic behaviour, such
as statechart diagrams, sequence diagrams, collaboration diagrams, and
activity diagrams, and they are based on different paradigms/techniques.
-
dynamic behaviour is also modelled in other diagrams, not specifically
intended for this; for example, in a class diagram we may have
-
invariants for active classes or for the whole model,
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pre-post conditions on operations of active classes,
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concurrency properties of operations,
-
signal reception specifications,
-
........
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an aspect of the dynamic behaviour of a part of a system may be described
simultaneously in several diagrams of a UML model, so that there is the
need of developing methods, techniques and tools to
help to avoid to introduce inconsistency in a model.
-
most of the semantic variation points in the UML are related to dynamic
behaviour (for example, the policy for handling the event queue in
statecharts).
-
........
The purpose of this workshop is to bring together researchers and practitioners
from academia and industry to report on their experiences with developing
precise semantics for the dynamic behaviour of UML models.
This one-day workshop will be the first on the particular topic of
the semantics of the dynamic behaviour of the UML,
but it ideally follows a series of successful four workshops on strengthening
the UML semantic foundation organized at the OOPSLA and ECOOP conferences
in the last two years, where this particular topic raised many questions
and lively debate. Presentations and discussions at this workshop will
focus on identifying the challenges, recognizing limitations, and analyzing
proposed semantics for the dynamic aspects of UML.
The results of these discussions are being collected in the
The
precise UML
group
FAQ (Frequently Asked Questions) document. The FAQ will provide answers
to questions, clarifying the role and need for precise semantics, the different
approaches that can be taken, and highlight key problems.
Last Updated: July 27, 2000