To identify architectural concepts and principles relevant to the potential users of a future standard, we realized we needed to understand the roles which architectural descriptions may play within system life cycles. While development
of a full “concept of operations” for architectural descriptions is left to the Working Group, the APG identified two fundamental ways of applying architectural precepts: architecture as design and architecture as style.
The first way is to use an architectural description as the vehicle for expressing high-level system characteristics that define and organize its major elements and their interrelationships.
The architectural description is used to communicate between client and developer to aid clarification of requirements and assess their impact on system design. The architectural description is often developed through an evolutionary process from the initial expression of a system concept as a high-level abstraction to one of a more detailed and tangible expression that is widely accepted as being an expression of design. The second way is to use a subset of the information used in a full architecture description to capture a style to
facilitate certain common attributes among systems, ranging from system compatibility, interoperability, (component) interchangability, to (system) replacability.
An architectural style is a set of patterns or rules for creating one or more architectures in a consistent fashion. There are many ways to capture and communicate a style [1, 2]. A reference model can be used to embody a style. Style is a partial characterization of a system; it does not represent the complete
architecture for a system, but is a template for specifying the architecture of a specific system.