Worse, even if the tool is later updated to include the feature you would have needed,
there will be little chance of making the wholesale changes necessary to take
TABLE 14.1 Basic Meta-Metamodel Concepts
ER UML OPRR
The basic model elements: Entity Class Object
. . . are connected by these: Relationship Association Relationship
. . . and both store information in these: Attribute Attribute Property
WHAT IS NEEDED IN A DSM ENVIRONMENT 367
advantage of it. Updating existing models for such a large change in a metametamodel
will often be rather like porting object-oriented code to a functional
programming language.
Contrast this with improvements in the other categories, for example, notation or
modeling tool functionality: there your modelers can bene?¬?t from the updates easily,
without having to update models. It is also worth noting that in our experience as tool
vendors, the meta-metamodel is something that is hard to change later: all the code of
the tool is implicitly dependent on it.
Explicit Concept of Graph Early versions of tools tend to handle the objects of a
model as one large cluster. This is rather like writing a program in one code ?¬?le: it will
work ?¬?ne for a small case, but will not scale to be useful in real-world cases. There
must thus be an explicit concept of a graph: a set of objects and associated
relationships.
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