How to track assembly components inventory

[DPS]

I am building a database for tracking inventory of garment items that get used in the fabrication of clothing. So I have the following tables built:

-Raw Materials (buttons, fabric etc)

-Garments (Simple table with the garment name/ID)

-Garment Line Items (List of each Raw Material use in above garment)

-Work Orders for Garment fabrication

-W.O. Line Items (table of each garment made in the above PO)

So now my dilemma is to figure out how many of buttons #1, 2, or 3 have been used up. The real issue is that various pieces of garment can use each button type in various quantities.

With this structure, I can easily find the summary of each garment made and we know how many buttons on each of those garments use but how do I create a calculation that will give me the total number of each button type used?

For instance:

Total number of Garment A * 2 buttons

+Total number of Garment B * 6 buttons

+ Total number of GArment C * 3 buttons

= total number of buttons used.

Any advice on how to merge this data can get the result I am looking for?

Thanks.

[comment]

See if this can get you started:

http://fmforums.com/forum/showtopic.php?tid/197316/

[DPS]

I think that does it. I look a quick look a the LiquorInRange file and it looks like exactly the same problem. I'll study it and work off that.

Thanks.