Firms need to consider how much buffer stock to hold as there are costs involved
Storage costs include rent for the warehouse and also the non-obvious costs of heating, lighting, refrigeration, security, etc.
Wastage costs are the costs of throwing away useless stock. The longer a business holds stock, the more likely it is to create waste. Stock gets physically damaged or perishable food spoils as time goes on
Capital tied up in stock is unproductive and could be used more productively elsewhere