As a practitioner I want to be able to:

• select an existing data type
• create a simple or structured data type
• create a “compound” (or complex) data type, easily.
  * 
expand/collapse views of compound data types, so that I can___
  * 
navigate between levels in a compound data type, so that I can___
• edit an existing data type
• remove an existing data type
  
…so that I can use the data type when creating a decision related asset.