The metamodel is the grammar of Keystone EA™. It defines the kinds of things you can model — 19 object types grouped into 7 layers — the 6 relationship types that join them, and a complete rule set governing exactly which links are valid.
Every element in a Keystone EA™ model is an instance of one of these object types. Each belongs to exactly one layer and carries a precise meaning.
Relationships carry meaning through their line style and arrow head. One is universal; the other five are qualified and governed by the rules below.
Each glyph shows direction from source to target. Composition carries a diamond at the containing end. Flow uses a hollow arrowhead, Realization and CRUD a solid one (CRUD dashed), and Supporting an open chevron. Connection is a plain, undirected line — the only relationship valid between every pair of objects.
This matrix is the heart of the metamodel: for every source → target pairing it shows which relationship types are permitted. Read a row as the source object and a column as the target. Toggle a relationship to isolate it.