You'll need a related "part assembly table" that functions much like the line items table of an invoice for each product to list the parts and quantities needed to assemble the product.
Product::ProductID = PartAssembly::ProductID
Parts::PartID = PartAssembly::PartID
You can then use a portal to PartAssembly on a Product layout to list all parts, and the quantities needed to assemble one item.
You can even make Product and Parts two table occurrences to the same data source table. That way a single inventory table can list inventory for both parts and products.
Do I need one PartAssembly table for each Item that I am building?
Just the one table. You get groups of PartAssembly records for each product and you can tell they are for the same product because they will all have the same product ID number. That's where portals become very useful here as you can see all the Parts for a given product by setting up a portal to PartAssembly on your Product layout.
I have a similar problem but am a more visual person.
I have inventory that is made of components (sets) and they get shipped from person to person.
My goal is to have one page that will show:
Set Name, Where it belongs, where it has been, who currently has it, whats in it.
I have read about portals in other posts but am completely lost on how to set this up. PLEASE HELP!