<Li> The composite of the design architectures for products and their life - cycle processes . </Li> <Li> The structure of components, their interrelationships, and the principles and guidelines governing their design and evolution over time . </Li> <P> One can think of system architecture as a set of representations of an existing (or future) system . These representations initially describe a general, high - level functional organization, and are progressively refined to more detailed and concrete descriptions . </P> <P> System architecture conveys the informational content of the elements comprising a system, the relationships among those elements, and the rules governing those relationships . The architectural components and set of relationships between these components that an architecture description may consist of hardware, software, documentation, facilities, manual procedures, or roles played by organizations or people . </P>

Five steps of the information system description framework