By using the net requirement calculation, the available stock is 80 units.
Given data:
Inventory On Hand = 100
Scheduled Receipts = 20
Net Requirements = 10
Safety Stock = 30
Available Stock = Inventory On Hand + Scheduled Receipts - Net Requirements - Safety Stock
= 100 + 20 - 10 - 30
= 80 units
So, the available stock is 80 units