We use a product by the gallons. I get it in 50-gallon drums.
CUSTOMER SHEET> When I enter a customer, I want to say “This customer needs XX Gallons”
INVENTORY SHEET > Have a running total of “GALLONS NEEDED” that is a SUM of “This customer needs XX Gallons”
IN INVENTORY GALLONS NEEDED ORDER XX GALLONS
When I get more 50 -Gallon Drums in, it will add to the inventory. When I use XX Gallons it will subtract from inventory. IF inventory is < 100 Gallons, order, IF Gallons needed is > IN INVENTORY order that amount + the extra 100 gallons to keep in inventory.