IA Architecture - Activity that aggregates the functions of developing IA operational, system, and technical architecture products for the purpose of specifying and implementing new or modified IA capabilities within the IT environment. [DoD Directive 8100.1, 19 Sept 2002]
IA Architecture - An abstract expression of IA solutions that assigns and portrays IA roles, and behavior among a set of IT assets, and prescribes rules for interaction and interconnection. An IA architecture may be expressed at one of three levels: DoD information system-wide, DoD Component-wide, or Defense-wide. DoD Component-wide and Defense-wide IA architectures provide a uniform and systematic way to assess and specify IA across multiple, interconnecting DoD information systems and to ensure that they take advantage of supporting IA infrastructures. E2.1.24.