Functional Architecture

Functional architecture is architecture that's independent of the technical implementation of the system, which is more stable across product families and generations to derive a sustainable physical architecture.

Functional architecture is defined as "Architecture based on functional elements, functional interfaces, and architecture decisions." (Tim Weilkiens, Jesko G. Lamm, Stephan Roth, Markus Walker. Model-Based System Architecture. Wiley. 2015).

Technology changes, but the domain-related functions are stable. For example, the high-level functions to play music are the same for a record player as for a music streaming service. None of the leading music streaming providers are among the leading record player companies from the past. First, you should focus on providing excellent services to your customers, and then you focus on the technologies that implement the functions.

At first glance, it seems trivial to describe functions independently of technologies...