Assembly Design > Assembly Design > Using Assembly > Working with Assemblies > About Using an Assembly Bill of Materials (BOM)
About Using an Assembly Bill of Materials (BOM)
The assembly Bill of Materials (BOM) provides a listing of all parts and parameters in the current assembly. The BOM and mass properties for the assembly are always based on the Master Representation and the components in the Master Representation. To generate an assembly or sub-assembly BOM, click Model > Bill of Materials and select one of the following options:
Top level—Generates a bill of materials for the top level assembly.
Subassembly—Generates a bill of materials for the selected subassembly.
You can customize the BOM by doing either of the following:
Customize the text output format for a particular form of presentation and content.
Use Drawing report tables to create the BOM in table format in drawings.
In the assembly BOM, you must still list nongeometric assembly features that do not have representable geometry such as glue, paint, and solder (referred to as "bulk items").
BOM and Mass Properties Behavior in Skeletons
When working with a skeleton model in an assembly, a Bill of Materials (BOM) is generated with component information and mass properties information that accurately reflects the design models and either the default or user-specified mass properties. However, the assembly BOM and assembly mass properties ignore skeleton models entirely when working on parts.
BOM and Mass Properties Behavior in Master Representations
To obtain the full BOM or the mass properties of the Master Representation while working with a simplified representation, you must switch to the Master Representation. Included components are included in mass property calculations because they are in session. It does not include excluded components unless they are in session. Mass properties only reflect what is currently on the screen. The BOM lists all components of assemblies that are in session. Unless the Master Representation is in session, the BOM is not accurate. PDMLink provides the full BOM without retrieval of objects. In Drawing report tables, the BOM is available only when you retrieve an assembly as the Master Representation.
For substituted objects, there is access to the names of both the original object and the substituted object. The mass properties of the substituted component are available because the component is in session. If they have been assigned through Interchange mode, the mass properties of the original object are available in the substituted component.