D-AG0003: sufficiently extensible to allow for future evolution.. ..etc.

Kicking of the discussion of goal D-AG0003:

CURRENT STATEMENT:
To develop a standard reference architecture for web services that: [snip]
 is sufficiently extensible to allow for future evolution of technology and of business goals 

MY COMMENTS:
I think the "extensible to allow for future evolution of technology" goal is fairly clear. Critical success factors for this would be, for example, ensuring that the architecture  
(A) separates the transport of data or means of access to web services from the web services themselves
(B) description of web services be clearly separated into abstract descriptions ("what") from their concrete realizations ("how"), or put another way, separate design time aspects from run-time aspects
(C) technologies using this architecture should allow for extensibility via inheritance, i.e., deriving one type from another

The "extensible to allow for future evolution of business goals" is a bit more complex. It's hard to know how business *goals* would evolve. But taking a conservative guess, critical success factors for these would include:
(A) technologies following this architecture should not impede the development of complex interaction scenarios likely for future business interactions
(B) security policies, handling various QoS aspects, negotiation of service level agreements (SLAs) must be facilitated by technologies conforming to this architecture. 

Thoughts? Comments?
Nilo

Nilo Mitra
Ericsson Internet Applications, Inc.
phone: +1 516-677-1073
mobile: +1 516-476-7427
email: nilo.mitra@ericsson.com