What you are modeling are concepts or types. Certain items are instantiable meaning that you can create instances of the types you have modeled.
Creating an instance of a definition type
1 Create the definition first, and specify its properties. For example, create a Measure definition called Pay Grade, create a Person definition type called Pilot, and in its Measure property, click Choices and drag-and-drop (specify) a measure of Pay Grade.
2 Find the definition in the Explorer; in this case the Person definition called Pilot. Right-click it, and choose Create Instance. Name it “Fred”.
3 In the instance definition, specify a value for the instance property: in this example, specify GS14 as the value of the property Pay Grade.
Most definition types and some relationship types can have instance definitions in DoDAF 2, including the following:
