Re: Java Live | January 9, 2001

[Richard Beton <richard.beton@xxxxxxxxxx>]

"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
system:

* 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.


begin:vcard 
n:Beton;Richard
tel;pager:ICQ: 56840977
tel;cell:MSN/Hotmail: richardbeton@xxxxxxxxxxx
tel;fax:01794 833434
tel;work:01794 833458
x-mozilla-html:TRUE
url:http://www.beton.freeserve.co.uk/
org:Roke Manor Research Limited;Internet Technology & Networks
adr:;;Roke Manor: http://www.roke.co.uk/;;;SO51 0ZN;UK
version:2.1
email;internet:richard.beton@xxxxxxxxxx
title:Internet Consultant
note;quoted-printable:The information contained in this e-mail is confidential and must =0D=0Anot be passed to any third party without permission. This =0D=0Acommunication is for information only and shall not create =0D=0Aor change any contractual relationship. =0D=0A
fn:Rick Beton
end:vcard