The key to good architecture is simplicity. A few well-chosen modules and sensible communication paths are the aim. It also needs to be comprehensible, which often means visually represented. We all know that a picture speaks a thousand words.
Good system architecture is simple. It can be described in a single paragraph and summarized in one elegant diagram.
In a well-designed system, there should be neither too few nor too many components. This criterion scales with the size of the problem. For a small program, the architecturemay fit on (or even be done on) the back of an envelope, with just a few modules and somesimple interconnections. A large system naturally requires more effort and more envelopes.