Andrew,

Allow me to explain.

When you do a mechanical design you assemble parts in the assembly enviroment. Then you go into the drafting enviroment and make drawings of this assembly.

As part of making drawings, you can also pull up a table that list all the parts / sub assemblies and their quantities. This table is called a BOM or Bill Of Materials.

Now - is it possible to draw a 2D sketch in the drafting enviroment using symbols, and then pull up a BOM of all the symbols used.
This would have to apply throughout the sheets in the drawing.

I have seen a view ECAD (electrical drawing CAD).
Comparing to SE (even as 2D drawing tool) is very unfriendly in use.
It is like old AutoCad - you must know too many key-strokes for it to be usefull.

To others:
My comments in the first post still applies and stays unanswered.
Please let us know what ECAD system you use and how well does it integrate with SE.