Re: revised requirements

[Martin W Sachs/Watson/IBM <mwsachs@us.ibm.com>]

Hara-san,

In the long run, we should consider multi-party TPAs but I believe that
this should wait for ebXML phase 2.

In our IBM Research project, we initially had some grammar for multi-party
TPAs.  We later realized that there are some significant open problems for
multiparty TPAs.  For example, when party B and Party C exchange messages,
that affects the state of the conversation.  Therefore, it is likely that
party A must include the messages between B and C in its conversation state
tracking.  That in turn seems to require extra messages, which may not be
desirable.  A second (and seemingly opposite) issue is that it was believed
that some of the information that is exchanged between B and C should be
able to be hidden from A (for example, a discussion of wholesale prices
between two subcontractors), both in the TPA itself and at run time.  As a
result of issues like these, we decided to focus on developing the 2-party
TPA and leaving multiparty TPAs for the future.

One can construct multiparty relationships by combining 2-party TPAs.
Supply chain is a natural example but combining 2-party TPAs should work
for any multiparty relationship.  This seems to require additional work by
the application process.  However, one might consider providing function in
the run-time middleware to assist with the correlations between TPAs.

Regarding multi-party relationships in the Requirements draft, I belive
that you are referring to item 6 under "The specification shall:".  This
refers to the use of 2-party TPAs for multiparty relationships.  If any has
suggestions for clarifying this point, please speak up.

Regards,
Marty

*************************************************************************************

Martin W. Sachs
IBM T. J. Watson Research Center
P. O. B. 704
Yorktown Hts, NY 10598
914-784-7287;  IBM tie line 863-7287
Notes address:  Martin W Sachs/Watson/IBM
Internet address:  mwsachs @ us.ibm.com
*************************************************************************************



Hirotaka Hara <hara@soft.flab.fujitsu.co.jp> on 09/11/2000 06:13:11 AM

To:   Martin W Sachs/Watson/IBM@IBMUS
cc:   ebxml-tp@lists.ebxml.org
Subject:  Re: revised requirements




Marty,

> Here is the revised requirements document.  It benefits from the few
> comments I have received plus other improvements.
> In the next day or so, we will be asked for our input to the ebXML
> requirements.  It would be helpful if people could review the attached
and
> provide comments very soon.

The requirement document seems to focus on the TPA between specific two
parties. In real business, however, more than two parties are involved
to do business. We need to deal with multiparty TPAs as you pointed out
in your presentation.

Do we need a TPA among three roles?  Or do we construct it by combining
TPAs between two roles?

I think it is an issue we should discuss in the WG. There is a
description about multi-party business relationships in the requirement
document. But it is not clear enough for me.

---------------

Hirotaka HARA, Dr. Eng.
Senior Researcher
Software Laboratory
Fujitsu Laboratories Ltd.