Inventor 2015 - Cannot Change BOM Structure

by David Gate

Settings a component or sub-assemblies Bill Of Materials (BOM) Structure Default allows you to define how that component appears within each assembly it is placed in. Every instance of that component whether it has a BOM Structure of Normal, Inseparable, or Purchased adds 1 to its Item QTY in the BOM. Components that are children of Reference parents are "hidden" in the bill of materials and are not added to Item QTY. Children of Inseparable and Purchased components are hidden in a Parts Only Bill of Materials.

A component or sub-assemblies Bill Of Materials (BOM) Structure can be set within the Document Settings of that file.

Or it can be changed in the BOM of an assembly it is used in.

Changing this BOM Structure in either of these places updates the other. So if a part is used in multiple places its structure appears the same in every location. Handy. But there maybe times you want to use a component as a reference, maybe to help you with your assembly or geometry.

Luckily there is an option to allow you to control the BOM Structure of individual components within an assembly on a unique case by case basis. In the browser or graphics window you can override the Default BOM Structure with Reference.

This then allows the same component to appear in a BOM as both Reference and other BOM Structures.

But if you try and change those reference BOM Structures which have been overridden in the assembly then you cannot change them in the BOM or in the components documents settings. They appear locked, until you go back into the assembly and remove the override.