[Modeling] response ro Rado's UN case study

Renato Levy rlevy@i-a-i.com
Tue, 15 Apr 2003 16:01:59 -0400

those are my two cents (or wahtever its worth) about Rado's UN solution:

1- Class Diagram (complicated only, the simple is of no use)

The notation looks a little confusing to me, but I sense it at the correct 
level of abstraction. I would like to discuss Icons and perhaps semantics 
foe more complex environements *SC-UN) was not exactly challenging).

2- Interaction Overview

Loved It!!!!!!!! I can't stress enough. Besides giving a sense of phases of 
the intreaction I allows one to sees multiple pahts without getting bogged 
down in details. All in all it has the extra quality of promoting reusability.

One sugestion touhg, the players on each interaction fragment should be 
depicted in the icon of each fragment.

3- fragments

a) I like the generic idea of the multi-lifeline,  I have use it before in 
my design. I also like the "guard condition" to single an agent of the 
multi-line. I don't think it may cover all possible multicast cases.

This particular interaction fragment seems that the parallel block is not 
needed, since the optional block would suffice to express the behavior 
(pehaps it is there for demonstration purposes)

b) change chair
Similar to my own design to change chair interaction. Important note the 
use of place holder in defining the agent that is the chair (currect, new), 
the exact definitions are environment dependent and should be defined at 
the environment level.

I like the temporal notation for the loop. I've use it before and it is one 
of suggestions for temporal constraints (modeling area)

Rules of nomination have to be defined at environement on non-coloquial 
language (english is too plausible to misinterpretation)

c) vote
I support the idea of a loop expression which is reacher then automatic 
iterators can provide. Expression sytax should not be liable for dual 

d) result

Same remark as in the others, actual decision point should not be in 
english but rather a clear logic syntax.

All in all, I think Rado gavea lot of very good ideas....

Soon, I will comment on Hong's UN solution.

Renato Levy
Principal Scientist
Intelligent Automation, Inc.
7519 Standish Place, ste 200
Rockville, MD 20855
phone: (301)294-5241
fax: (301)294-5201
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