Comments on C4ISR Architecture Framework

Architecture is Situated:

Architecture, as an activity, is located within systems’ life cycles, the operational and
development environments, etc. Architectural products have multiple audiences drawn from
multiple system stakeholders. These products should relate to those stakeholders’ needs, in the
context of other products they need to do their jobs (e.g., Statements of Need, Operational
Concepts Documents, System Specifications, Top-Level Design Documents, Strategy, and
Policy Memoranda, etc.). Products also have ownership and other roles.

We do not see that the CISA document addresses this context of Architecture. E.g., to
distinguish architecture from any other modeling activity, it is important to locate architecture in
the life cycle as distinguished from requirements and design. What is the relation of proposed
architecture products to existing requirements documents? Are CISA architecture products
intended to supersede, summarize, and enhance other products? How are these products kept in
synch with each other and with other documents?

Another aspect of context is the location of architecture in the problem v. solution “spaces”—
this distinction would be useful to understand the present CISA document. Most uses of
architecture distinguish descriptions of the problem from prescriptions of the solution. E.g., the
IEEE definition addresses this by making architecture the “highest level” of abstraction relative
to design considerations.