Not every missing item has the same consequence
A missing essential can end a shopping mission. A missing optional variation may leave a useful substitute. Stock planning should preserve that difference instead of treating every item as an equivalent line in a forecast. The mission, the substitute and the time needed to recover all change the decision.
Read the physical limits
Storage, shelf life, replenishment access and handling requirements constrain inventory. Extra stock may reduce one risk while creating damage, waste or a congested workspace. A stock plan should explain where the item will be held and how it will reach the customer-facing location. The inventory record cannot create physical capacity.
Separate known from expected
Saleable stock, reserved stock, a planned delivery and an uncertain receipt are different states. Combining them into a single confident availability message transfers uncertainty to the customer. The service promise should reflect the state that can be supported, including what happens when an expected delivery does not arrive.
Review the system around the number
A useful availability review also considers substitutions, discrepancies, damaged stock and customer effort. Repeated shortages can come from the range, receiving, allocation or the replenishment routine, not only the order quantity. More inventory can mask those problems temporarily while making the eventual correction more expensive.