I have an inventory project, and there are some business process validation.
the core flow of the project is that
supplier put stock item in the inventory and customer take stock item out of the inventory.
and what i want to ask is that
i have a business process validation to check the stock item is in the inventory before a customer can take that stock item
if customer A is in the phase of checking the stock available or going to take the stock item out. No other customers can perform stock taken operation on that item.
Where i should put this kind of operation.