Database Reference
In-Depth Information
Table 5: Requirements Canonical Model
as the data fl ow diagram (DFD), the entity-relationship diagram (ER), the class diagram
(CD), the state transition diagram (STD), the statechart (SCT) and use cases (UC).
Table 7 shows that the best-suited conceptual model is the class diagram, as its fi tness
is greater than all the other conceptual models (or, at least, of all the ones that have been
considered in the calculation). The fi tness value of the class diagram is 0.71, which means
that it can express 71% of all the RCM propositions.
Determining Method and Technique Fitness
As mentioned above, different methods and techniques employ different conceptual
models, such as data fl ow diagrams, entity-relationship diagrams, use cases, state transition
diagrams, etc. This means that, once we have determined the fi tness of a model, this fi tness
can be extrapolated to the methods and techniques that use this model. For example, after
determining the fi tness of a data fl ow diagram, we can consider that all the methods and tech-
niques that use this model, that is, all the structured methods and techniques, will be equally
fi t. The same could be said for the other models, such as use cases or state transition diagrams
with respect to object-oriented and real-time methods and techniques, respectively.
But the situation is not as simple as this, because most methods and techniques use
more than one conceptual model, with the aim of expressing different viewpoints about the
problem domain. Accordingly, for example, the structured methods and techniques use, for
example, DFD and ER, whereas the object-oriented methods and techniques use, among
others, CD and UC. This means that we will have to consider all the conceptual models used
jointly rather than each one separately to determine the fi tness of a method or technique.
