Model-Based System Architecture, 2nd Edition

8Architecture Description

In Section 5.3, we define architecture as idea. Ideas are not observable and need communications and explanations to related stakeholders for successful system realizations. Architecture descriptions are tangible artifacts communicating and explaining ideas about systems-of-interest. Not only system realizations benefit from architecture descriptions. Observation of realized systems does not reveal each idea or justification leading to the system's existence [58, 266]. Therefore, architecture descriptions provide substantial benefit for maintenance and evolution of systems. As better architectures are expressed as better systems-of-interest, follow the ideas of their architects (see Figure 5.1).

Architecture descriptions shall document how selected solutions satisfy requirements or address concerns. Along with descriptions on how solving stakeholder problems, architecture descriptions document the inevitably taken or made architecture decisions including the related architecture rationales. That is, architecture descriptions express the how and the why of solutions.

Architecture starts to exist as initial solution hypothesis while analyzing and validating business and stakeholder requirements. Stakeholders may impose base architectures captured in concepts of operations (ConOps).¹ Frequently, such imposed architectures are not explicitly described. Often base architectures appear to the involved parties as obvious as not worth to spend effort expressing ...