RE: [ebxml-bp] Re: Updated InformationDistribution, Notification Patterns and Performs (Roles

["Dale Moberg" <dmoberg@cyclonecommerce.com>]

Comments in line

From: Kenji Nagahashi [mailto:nagahashi@us.fujitsu.com] 
Subject: Re: [ebxml-bp] Re: Updated InformationDistribution,
Notification Patterns and Performs (Roles
Hi, I have difficulty understanding why responding role is to be bound
with 
  responding activity. 

Dale> I think the simplest way to understand this is that there are two
roles in the BT and both are engaged in RequestingBusinessActivity and
in RespondingBusinessActivity. But we want to say which role goes with
which "side" of the activity. By convention, the initiator of the
activity is picked as the place to associate a Role with an activity. So
one role is associated with the RequestingBusinessActivity, and is the
initiator of that activity.

The other Role is the initiator of the RespondingActivity. Because each
of the RequestingBusinessActivity and RespondingBusinessActivity has a
unique nameID value to refer to, that permits each Role to be uniquely
associated with an activity. 

Kenji continues>

My simplistic belief has been that both of two 
roles are bound when initiator initiates Requesting Activity.

Dale> This is true. However, to mark which Role goes with what, we need
a convention, using unique IDs, to associate two unique Roles with the
sides in the business activity. So, for example, the receiving side of
the RequestingBusinessActivity (which is also the initiating side of the
RespondingBusinessActivity) is associated with the
RespondingBusinessActivity. The initiating side of the
RequestingBusinessActivity (which is also the receiving side of the
RespondingBusinessActivity) is associated with the
RequestingBusinessActivity. That is, we adopt a convention to link the
role to the activity it "initiates" Could we have linked roles to
activities in other ways? Yes, we could have linked both the same
activity but one in an initiating and one in a receiving role, for
example. Other permutations are possible.  In other words, there are
several other ways to describe this association, but they would also
just be conventions for marking the same associations.

Kenji continues: Could anyone direct me to good reading/ML posting for
understanding modeling rationale?

Dale> I am not sure how to help here because we are just discussing a
notational convention for indicating an association between two sets of
things -- the 2 sides of the business activity and the 2 values for
roles.

Here is a set theoretic way of viewing the model fwiw.
Let our roles be the set R = { R1, R2} and let our sides be the set S =
{ S1, S2}. We want to be able to express the associations in the cross
product, R x S which is:

<R1, S1>, <R1, S2>, <R2, S1> and <R2, S2>

and where by an association we mean a selection of two pairs from the
relation (such as, the set { <R1, S2>, <R2, S1> } that use all the
elements from both sets. We picked out ID values of elements of two
Roles and the two activities of a BT. And we have a notation that
expresses the model. There are other ways to write down notation that
captures that logical model, and as long as they fulfill the logical
requirements, they would be just as good (or bad) as the one we have it
seems to me. I am not sure that will help, but it is a way I think about
it.