Thing is the top of the DoDAF 2 metamodel hierarchy. All DoDAF 2 artifact types inherit from Thing. Thing is not instantiated as a definition type; it is equivalent to the definition type itself.

An example of part of the DoDAF 2 metamodel that shows Thing at the top of the hierarchy is expressed below:

Subtypes of Thing as instantiated in System Architect, are as follows (click each to see their respective pieces of the overall metamodel):