Inventory qty

Hello what is the process to inventory

I have input stock with a total of 10 qty and at the time of sale process in stock, why not reduce qty in stock

stock qty 10 and than stock out via sales 2 qty and than we back to inventory stock the total qty the same 10 not reduce.
please help and advice so many thank you.

you have to copy the sales invoice to make a delivery report.
that would mean the stock is out of the inventory

Read the three Guides on inventory management.