Systems architecture foremost serves us humans: those who design, implement, operate, use, maintain, and enhance a given system – because our intellectual capacity and receptivity is limited. Technology would work perfectly fine without discernible architecture, but we could not design and implement such a system in the first place to have the desired functionality and only that functionality, if not for form and organization. Thus, the purpose of systems architecture is to make systems understandable and intellectually manageable; it is the architecture of a system that allows an organization to implement and operate it.

Systems architecture creates structure and thus predictability. It is a system’s structure that allows analysis and reasoning about its behavior. Predictability is especially important when altering an existing system: Without architecture, we could not predict the result of some extension or alteration; thus we would be confronted with risk of malfunction and undesired behavior each time we attempted even the smallest change.

Systems architecture is communication: The architecture enables third parties to understand how a system is organised, what it does, and how it works. Systems architecture allows for development and operations at scale: a large number of development and operating personnel can jointly work on the system, and new staff can be integrated quickly, because everyone can understand the overall structure yet work in his or her confined, isolated part of the system without interrupting others.