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Re: Java Live | January 9, 2001

"Gerald H. Hilderink" wrote:

> The UML does not really capture data-flow modelling. In fact, the UML
> totally moved away from data-flow modelling. The reason is that data-flow
> does not easily match with method-calls, inheritance, polymorphism, and the
> other OO stuff.

I feel there is a simpler explanation than this. Consider two distinct but related ways of modelling entities in a

* class modelling deals with the structure of classes, their inheritance and polymorphism
* data-flow modelling deals with information flowing between *instances*, whether these are OO object or (active)
processes (in the occam sense).

Most OO designers focus on class modelling (a.k.a. entity relationship modelling) rather than instance modelling so
data-flow diagrams don't seem very useful. It's when you come to think about concurrency that modelling instances
becomes important. So hey presto, the occam data-flow approach fits very naturally.

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