In this paper we introduced a new priority rule algorithm in human queues. The suggested method is applicable in human lines with different demands (serving times) for different customers. In this method, the waiting time for each customer is related to the volume of demand. A common example of such a system is a bakery line. The usual priority rule algorithm in this kind of queue is First-In-First-Out where its waiting time is not optimal. In this new priority rule algorithm, the login time is saved for each customer and for choosing the customer for the service at each turn, the ratio of waiting time to the service time is calculated for each customer, and the customer with the highest value of this ratio is selected for the service. A mathematical model was extracted to simulate the algorithm and the model indicated that waiting time could be optimized up to 25%. In addition, in our case study the waiting time was reduced by 20 % after the implementation of the algorithm. Another advantage of our approach is the prediction of waiting time by an intuitive method. Moreover, the volume of demand is regulated automatically by using this algorithm. This algorithm was developed in a queue ordering system and the results are presented. The result proved the advantages of this algorithm. The customer satisfaction was also measured that showed improvements.