Top Level Comments

The presentation represents one (and not the only) very useful view of the AITS architecture, namely a view that focuses on architectural properties that the AITS architecture must have to achieve Rick's 4 Cs (complete, consistent, correct, and current) plus Rich's E (evolvable).

This is a good level for the Architectural Review Team to ponder.  One of the questions asked of the review team was, "What role can the Review Group play in terms of the long-term framework?"  If this document is related to that question, then its worth making these additional comments:

• The High Level Framework is not a long term architecture -- it is needed now.  And all AITS programs need to begin to understand this view of the architecture and contribute to a group understanding of it.
• This is also not the only view of AITS that the Architecture Review Team should contribute to.  We should also be identifying technologies that might cause discontinuities, identify process questions about how to get componentware into wide spread use, and generally provide expertise to improve AITS in the most useful high level ways we can.

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Detailed Comments

• The word framework in High Level Framework is used in two senses making it ambiguous and confusing.
• as a meta architecture, that is the perspective of architectural properties that all components must abide by.  Most of the discussion on ilities is apropos to this sense of the word.  But describing the framework as a "level above the architecture" is then confusing since it is still architecture.
• as an organizational, process, or presentational device to insure that we look at the relevant aspects of the architecture.  The identification of the architectural capabilities and then their use in foils to show Trends in Architectural Capabilities, Comparison of JTF and ALP, and  Proposed Enhancements are examples of the use of a framework to draw out different information or consider different aspects.
Both senses are useful but they are different.  Both are areas where the Architectural Review Team can help.
• The category scheme is very vague and high level to me.
• Behavioral Control, Component Interaction, and Component Composition especially overlap.  So do Information Representation and Semantic Expression, the former seemingly a subset of the latter.
• The category scheme seems to be descriptive and not really constructive, leading me to view it as more the latter kind of framework.
• I'm not sure how easy it would be to map the wide range of technologies on all the AITS slides into these categories, whether any two people would agree, and whether the result would be useful.
But I do agree this is still somewhat useful to try to do in some cases like Information Representation, to see trends like the move toward finer granularity and flexible composition, and to compare roles played by objects and agents and CORBA versus RMI (which do not show up if you just consider ilities).
• I do see it as being very valuable to identify the various ilities and analyze them.  By their nature, ilities cut across systems and one wants a way to insert them into systems that evolve and to control their policies.  I see us doing this for reliability, network management, scalability, composability, ... mostly separately now built in to systems in a brittle way, but we are beginning to see the pattern for inserting these into composable systems.  That is what my OMG OMA NG paper and the upcoming January workshop are leading toward.
• on the foil Dimensions for Extending Current AITS Architectural Capabilities:  I agree on all the areas of extension but am not sure I agree that the framework of dividing the world into Object Management Services, Agents, Components, and System Control Services got us there or that the categories are non-overlapping.  So it might just be useful foilology, not a meta architecture in the first sense.
• on the foil Selected Technology-Enabled Enhancements, I have a similar comment.  I agree the enhancements are reasonable but am not sure the high level framework really got us to this conculsion.  (Yet another meaning of framework seems to be creeping in here in this foil, one that is sort of synonymous with DSSA, that is patterns for subarchitectures of the whole.)
• on the foil Proposed Enhancements, similar comment

Hope this helps,
Craig