Re: [soa-rm-ra] what is a generalized SOA RA?

[Ken Laskey <klaskey@mitre.org>]

Jeff,

Thanks for the clarification.  Given the experience of struggling over words for the RM, I can see where a hasty concatenating of words can lead to confusion.

I'd suggest the following:

1.x What is this Reference Architecture

The SOA Reference Model defines reference architecture as “an architectural design pattern that indicates how an abstract set of mechanisms and relationships realizes a predetermined set of requirements.” More precisely [ref TOGAF], a reference architecture can be described as an architectural pattern that provides a set of predefined subsystems, specifies their responsibilities, and includes rules and guidelines for organizing the relationships between them. It is possible to define Reference Architectures at many levels of detail or abstraction, and for many different purposes. In fact, the reference architecture for one domain may represent a further specialization of another reference architecture, with additional requirements over those for which the more general reference architecture was defined.

This wording ties back to the RM but also incorporates the TOGAF definition.  For those not expert in TOGAF, I don't think there is any contradiction.  For those who are familiar, I think it corrects the ambiguity.

Talk with you in a couple hours.

Ken

On Nov 13, 2007, at 5:59 PM, Jeffrey A. Estefan wrote:

Ken,

This is straight from TOGAF v8.1.  Prefer you use the term "architectural pattern" (and not architecture pattern or architectural design pattern).

 

Cheers...

 

 - Jeff

 

=======

Architecture Patterns and Design Patterns
The term "design pattern" is often used to refer to any pattern which addresses issues of software architecture, design, or
programming implementation. In Pattern-Oriented Software Architecture: A System of Patterns, by F. Buschmann, R.
Meunier, H. Rohnert, P.Sommerlad, and M. Stal, John Wiley and Sons, 1996, ISBN 0-471-95869-7, the authors define these
three types of patterns as follows:
* An Architecture Pattern expresses a fundamental structural organization or schema for software systems. It provides
a set of predefined subsystems, specifies their responsibilities, and includes rules and guidelines for organizing the
relationships between them.
* A Design Pattern provides a scheme for refining the subsystems or components of a software system, or the
relationships between them. It describes commonly recurring structure of communicating components that solves a
general design problem within a particular context.
* An Idiom is a low-level pattern specific to a programming language. An idiom describes how to implement particular
aspects of components or the relationships between them using the features of the given language.
These distinctions are useful, but it is important to note that "architecture patterns" in this context still refers solely to
software architecture. Software architecture is certainly an important part of the focus of TOGAF, but it is not its only focus.
19/12/2003 Architecture Patterns 2 of 5
In this section we are concerned with patterns for enterprise system architecting. These are analogous to software
architecture and design patterns, and borrow many of their concepts and terminology, but focus on providing re-usable
models and methods specifically for the architecting of enterprise information systems - comprising software, hardware,
networks, and people - as opposed to purely software systems.

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Ken Laskey

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