Share 'Tracking/managing inventory'

How do you track your available inventory?  Right now I'm putting all my data into Excel spreadsheets, but they keep getting more and more complex, and I keep finding a need for more and more of them.  On one sheet, where I'm also calculating unit costs, I'm tracking a total inventory of how many were made, how many were "lost" (cracked, had extrusions, taste-tested, etc.), how many were sold, an…