Business Goals and CSFs

Even though its still August, I felt that it is appropriate and timely 
to publish these proposals for the requirements document.

They are similar in tone to some goals and CSFs that I sent on the list 
a couple of months ago; but have been considerably cleaned up on and 
tightened up.

IMPORTANT: This message `counts as' a request for discussion and 
closure also. It may be that final closure will have to wait for the 
f2f.

We have one new goal, that captures the fundamental intention to be 
business friendly:

======================

AG007 Business Friendly
The Web Services Architecture must provide a framework which reflects 
the evolving needs of businesses as they conduct business using Web 
Services
Critical success factors:
AC023 Peer-to-Peer Interoperability
AC024 Multi-party Interactions
AC025 Service Re-use
AC026 Semantic Descriptions
AC027 Relationships

There may be other CSFs that relate to this goal, I simply list the new 
ones.

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The first new CSF relates to peer-to-peer interoperability:
AC023 Peer-to-Peer Interoperability
The Web Services Architecture must support interoperability between 
peers as well as client-server interactions
AR023.1: The WSA must permit a rich range of MEPs, including patterns 
such as request-response, publish-subscribe, forwarding, proxy-ing and 
event notification
AR023.2: It must be possible for peers to have persistent identities 
that are distinguished from any other attribute – such as their 
location or type
AR023.3: It must be possible for peers to interact without the required 
presence of any third party intermediary
AR023.4: It must be possible for peers to discover each other

The fundamental issue here is that business is naturally a peer-to-peer 
kind of activity and that the WSA must support the way business is 
conducted rather than force everything into a client-server 
straight-jacket

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AC024 Multi-Party Interactions
Web Services must be able to support N party interactions, such as 
auctions, escrow services, proxy services, broker services
AR024.1: It must be possible to quote, verbatim and modified, messages 
within top-level messages, to an arbitrary depth
AR024.2: It must be possible for web services to support interactions 
where one of more parties of the interaction are anonymous
AR024.3: It must be possible to express multiple receivers and to 
express ‘wait’ points in service orchestration

This CSF and its associated requirements reflects the fact that 
business is not always 1-1 but often involves many parties.

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AC025 Service Re-use
The Web Services Architecture must provide a framework for the 
effective re-use and composition of services
AC025.1: It must be possible to compose services dynamically, on the 
fly, as well as statically
AR025.2: The service composition model must permit the expression of 
and the evolution of composed relationships
AR025.3: It must be possible to express sequencing and nesting of 
services, and the flow of information between services
AR025.4: It must be possible for third parties to verify performance of 
services (where performance includes results as well as timeliness)

This CSF is an attempt to crystallize some of the composability 
requirements which are currently somewhat scattered.

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AC026 Semantic Descriptions
It must be possible to characterize a Web Service so that its semantics 
are clear to an automatic system
AR026.1: The Web Services Architecture should be aligned, where 
appropriate and possible with the Semantic Web. This may require some 
modification of current technology choices. (This is a version of 
D-AC009)
AR026.2: It must be possible to publish references to an ontology in a 
Web Service description
AR026.3: It must be possible to characterize a service using purely 
publicly observable semantics:
The semantic description of a Web Service should rely on public 
explicit agreements
The descriptions should be based purely on observable characteristics 
of services and principals

This is a critical CSF; since it targets directly the needs of an 
automatic system as opposed a human guided system. Chris Ferris has 
talked about the difference that a human can make when navigating the 
web; this CSF focuses on what is needed to permit automatic navigation.

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

AC027 Relationships
It must be possible to model the identities, roles and relationships of 
principals involved in a Web Service
AR027.1: There must be proper separation of roles and identity in 
transactions:
AR027.2.1 Choreography and orchestration must be role-oriented
AR027.2.2 It should be possible to identify and authenticate a 
principal acting in a given role
AR027.2: Account for the many different time-scales over which 
relationships must be supported:
AR027.3.1 It must be possible for relationships to persist across 
changes in the environment
AR027.3.2 Temporal characteristics of relationships must be explicitly 
documented in Web Service descriptions

This too is a critical CSF (is that tautologous?) since it targets the 
foundations for security; which is itself critical to foster confidence 
in the use of web services.
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Received on Friday, 30 August 2002 16:08:53 UTC