Communicating Your Design - Autodesk Inventor 2010: No Experience Required - page 458

20. Click OK to change the parts list.
The balloon also updates to match the change to the item number
in the parts list. You could have made this change at the balloon, and
the parts list would've responded.
21. Save your work.
Adding an individual balloon is even simpler. You can also modify the balloon
to change its shape. And instead of showing the item number, you can display
the name of the component and even how many of it are in the assembly.
The balloon and parts list are merely representations of something that's far
more important to the assembly: the Bill of Materials and the knowledge that
Inventor automatically captures in it.
Bill of Materials
It's important that you understand that the Bill of Materials (BOM) isn't the
same thing as a parts list.
You should think of the BOM as the master document that records what parts
are in the assembly. Moreover, you can use it to alter the structure of the assem-
bly without having to reorder how the assembly was built. If you edit the BOM
from the drawing, you're actually changing the assembly as Inventor sees it.
A parts list is a representation of all or part of the BOM on a drawing. You can
edit its appearance above and beyond the changes to the BOM, but it's critical
that the BOM truly refl ect the state of the assembly.
Within the BOM, you can structure a component several different ways:
Normal Any part that you produce will most likely be regarded as a Normal
component in the BOM.
Phantom Sometimes the fi le structure of an Inventor assembly doesn't match
how it will be built. For example, if you assemble several components into an