Potential or expected sales will only be realized if the planned sales mix holds. If the sales from a liter of jin, as shown in Exhibit 9.15, are not what is expected, there will be a definite variance in income from that expected. A sudden drop in sales of normally popular drinks should be investigated. There could be any number of reason for a loss of sales. How large a variation should be permitted before an investigation is made? This depends upon the particular operation. A 1 to 3 percent variation probably does not warrant investigation, but beyond that point it is wise to find out whether something is wrong. Liquor is particularly susceptible to pilferage,theft, and a variety of fraudulent practices.