This system is designed to control beverage sale and therefore costs by setting a sale value on each bottle item carried in stock. The revenue value of each bottle is based on the standard size of the drink, the contents of the bottle and the selling price for each drink. The sales value of each drink is called the potential ( or standard ) sales value. The system requires as a basis for its operation, established standards for a bottle code number system, drink recipes, drink size, glassware and par stock. Whenever the bottle size, drink size or recipe change a new calculation must be made and recorded, as this can affect the price of a drink and should require the price to be reviewed.