Thanks for the mention BABU BASKARAN
Allow me to elaborate a little bit more on this question, an item can be assigned to a specific unit of measure schedule in which I assume you will have to include the following:
Unit of Measurement Schedule: Case12 (referring to a Case with 12 each within)
Base unit of measurement: Each
Conversion : 1 case = 12 each
I am quite sure that you already have an overall idea about the unit of measurement schedule. What I would like to add up is that you can definitely sell, buy and see this item stock and transactions in all the unit of measurement schedule levels (Case and Each).
For purchasing, you can restrict purchasing the item in a specific level which reflects your specific requirement, this can be done from the item purchasing option window (Cards> Inventory > Item Purchasing Options)
As for the sales, you can not restrict, but you may specify a selling unit of measurement from the price list window.
All in all, your bill of materials, and configuration will control how the item is purchased, manufactured, sold and most importantly reported.
Please never hesitate to share any further inquiries,