Use this window to connect parts to functions, or to view part information.
  You cannot modify an existing part
  using this form.
  The engineering function structure is a conceptual level of product
  construction. Functions can be arranged in a structure. Each function on the
  bottom level can also have parts and the corresponding part structures
  attached.  The purpose is to organize the product structure so that it is
  familiar to multiple disciplines and to help with the construction of a
  product without having to immediately decide all its properties. 
  A function is the intended use of connected part(s). One part
  can be connected to more than one function, i.e., it can have several
  functions in the product structure.
  If the Parts node is
  selected in the navigator and there is no Parts node for a function,
right-click and select Add, then  Parts to add a Parts node. On the root node this form
  will list all parts connected to the selected product and model. The form will
  the be read only. 
Design
  Product Structure
  Release Part
  Revision