To draw another analogy for the point of action, I
know your mind will be the point of action for
processing this e-mail as you read the e-mail. The
e-mail address and the english language is like a
service interface.
The SOA has many points of action, each point of
action potentially affecting many other points of
action. We can identify points of action in a SOA
relevant to the reference architecture. One question
we can ask is can we identify a point of action
meaningful to the reference architecture that would
not have a service interface?
Danny
--- Ken Laskey <> wrote:
> The following are from my notes at the ftf
>
> Point of Action (poa)
>
> - Frank: anchoring mechanism for numerous
> things, e.g. policy
> enforcement, evaluating needs & capabilities
>
> - Ken: how does poa relate to service
> interface? Frank:
> service interface includes actions you can perform;
> each instance of
> use consists of performing action; actual action is
> poa; interface
> vs. poa is class vs. instance relationship; the
> physical action is
> the point of action
>
> - [Ken] Given a policy is a desire of one
> participant and an
> agreement as part of the execution context for
> participants to abide
> by that policy (i.e. the other participant(s) agree
> to make that
> policy theirs), the policy enforcement point becomes
> the point of
> action for enforcing the agreed-upon policy.
>
> - [Frank alternative] A policy is a constraint
> that represents
> the desire of a participant. A contract is a
> constraint that
> represents the agreed desires of two or more
> participants. A [policy]
> enforcement point is the point of action for
> enforcing constraints
> that represent either policies or contracts.
>
>
> I've reread this and am still having problems
> differentiating between
> service interface and point of action. It appears
> that poa is more
> general because it is the location to which a user
> would send a
> command for action. If the receiver is a service,
> then the poa would
> seem to be the service interface. In the policy
> example, if the
> enforcement mechanism is accessed through a service,
> the PEP could be
> said to have a service interface.
>
> I still seem to be missing something.
>
> Ken
>
> ---
> Ken Laskey
> MITRE Corporation, M/S H305 phone: 703-983-7934
> 7515 Colshire Drive fax:
> 703-983-1379
> McLean VA 22102-7508
>
>
>
>
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