Re: [soa-rm-ra] Service Interface Model (graphic attached)

[Ken Laskey <klaskey@mitre.org>]

Jeff,

The former Fig. 20 (that is, in the March 26 v0.3) was the wrong diagram.  If you go back to the Feb. 20 version of the RA, Figure 16 is correct.  I haven't quite figured out when the unintended switch occurred, but I resent the intended one after our last call.  So my comments are meant with respect to the intended figure.

Now the figure you are discussing is Figure 25; this had appeared as Figure 21 in the February 20 draft and has been in the document in some form for quite a while.  We can discuss it (and correct as necessary) in its intended context.

Ken

On Apr 10, 2008, at 6:52 PM, Jeffrey A. Estefan wrote:

Ken,

 

There's abstraction and then there's ABSTRACTION.

 

For example, at the RM level, it's OK to state that an Information Model has Structure and Semantics; however, at the RA level, this is not enough detail.   This is why I show structure and semantics as applied to messages and data (payload) within the Information Model class.

 

In addition, the former visual model (Fig. 20) introduces new concepts like Action Level Policy, Precondition, Service Level Interaction Policy, Service Level RWE, and Action Presence.  Concepts for which I do not even know the source, RM or otherwise.  Nor have we even had a chance to debate the merits of such concepts.

 

Also in Fig. 20, Action is introduced and shown as associated with Message with the label "invoked via".  This is a somewhat dynamical view and not really consistent with our RA notion that messages "denote" actions (and events) and that actions "cause" RWE and events "report" RWE.  In the RM sense, we state that interaction is accomplished by performing actions against the service and this is realized via message exchange (although other "modes" are permissible, e.g., state changes to shared resources).

 

I think we all agree, based on feedback during the recent telecons, that we do indeed need to revisit our discussion of Action throughout the RA to insure consistency.  I'm definitely in agreement there.  But for this discussion, I was making an attempt at proposing a reasonable model for Service Interface, and one that would be readily palatable by the reader.

 

 - Jeff

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