SYSE.2:10 - Rationale

A System concept becomes useful to an engineering decision through concrete relations with other Systems and conditions, yet no single containing whole or representation captures every consequential relation. Linking use and System concepts makes the outside reason and inside proposal inspectable while leaving architecture selection to the applicable FPF patterns.

The link is intentionally small. One use claim, one concept claim, and one uncertainty can already reveal a missing bearer, harmful effect, or misplaced boundary. Fuller descriptions are justified by decisions they can change, not by a prescribed documentation sequence.