Several layers of stock control can be supplied, according to your needs, for finished/semi-finished lenses and for frames:
Booking in receipts
Report on average usage
Viewing stock levels
Setting minimum stock levels
Every sale of an item will reduce the stock level when the order is printed. This changing stock level will be used by the order entry program in deciding which semi-finished or finished lens to allocate to the job.
There are modules to book in receipts of frames & lenses in matrix formats, and also to suggest re-order quantities, for which the system calculates the suggested quantity based upon issues of the product over the last three months. Where different suppliers of semi-finished are used, the levels for the suppliers are aggregated together.