It was clear that even if there was a representation in what I call the Engineering Model in the CAD system for every functional component, it was still necessary to have the BOM outside the CAD system. There was no way the CAD system's capabilities for handling all of the extra fields and calculations that are required would be sufficient. I use the FBOM equally as a Project Management tool as well as a tool for managing the development of the product. I have found it useful to add many additional fields like component type (structural, mechanical, electrical, hydraulic, etc.), supplier information (multiple vendor names, part numbers, price quotes, lead times, etc.), and most importantly, what models the components are populated into as mentioned above.
I came up with this name because I had a list of components that were being used by various Modeling & Simulation (M&S) tools significantly before there was going to be an Engineering Bill of Material (EBOM) or Manufacturing Bill of Materials (MBOM). What I found was that there was a need to perform many engineering tasks (performance evaluation via M&S, physical integration & packaging, mass studies, cost analysis, reliability, etc.) with the functional components before committing to a product structure. The product structure is important in detail design, but it is not helpful to work with a final product structure prematurely, especially when multiple concept configurations must be considered. These functional components may be represented as fundamental engineering geometry only capturing interfaces and mass in a CAD system, an initial structural representation in a Finite Element Analysis program, one of several "blocks" in a Model-Based Systems Engineering model, etc. The very fact that some components have representations in multiple models (an engine may be have a dynamic performance model and have packaging and mass representation) makes it critical to track what components are represented where.
With a little work utilizing common lookup, sorting, and filtering functions in a spreadsheet information in the FBOM can be a powerful development and reporting tool.
Please feel free to contact me for more information on this if you are interested.