Two Types of BOMs
The two types of BOMs are Indented BOMs and Flat BOMs. In general, engineers and designers like to think in terms of Indented BOMs while purchasing likes to think in terms of Flat BOMs.
Take the example of a skateboard below. The Bolt is used in multiple levels of the assembly. There are 8 bolts in the top level, but there are 2 bolts in each axle assembly. Since there are 2 axles in each skateboard, there are 8+2+2 =12 total bolts in one skateboard. This is simple to think through for the skateboard analogy, but you can see how this would get extremely difficult for machines with thousands of parts, and dozens of assembly levels.
Both types are useful, but converting between the two is not something that a human can do accurately and efficiently. The secret sauce of QuickBOM is that it maintains both a flat BOM and an Indented BOM in one file. A whole bunch of macros and formulas keep them in sync.
The Flat BOM is stored in the Library tab of your QuickBOM file. There can only be one Library tab in each QuickBOM file.
The Indented BOM is stored in a CAD_<your BOM name> or MAN_<your BOM name> tab. There can be one or many Indented BOMs in one file.
Here’s what the skateboard would look like in QuickBOM.
When working with QuickBOM, multiple people can work in the same file at the same time. Some can work in the Indented and some can work in the Flat BOM, and you can always be confident that they will be kept in sync.