(1)模拟设立一个服务时间区间如7：00-20:00，或者限定最大服务人数；
(2)顾客到达时间随机，选择购票/签票/退票业务随机，选择人工/自动售票随机，同样的购票方式选择时选取人数最少的排队等待，随机情况需用随机数模拟实现。
(3)需要区分不同窗口或不同的自助售票机。
(4)接受服务/自助购票用一个随机数模拟时间表示。(1) simulate the establishment of a service time interval, such as 7:00-20:00, or limit the maximum number of services;
(2) the customers arrive at the random time, select the ticket / check / refund business random, choose the manual / automatic ticket random, and select the least number of queues in the same way of purchase, and random numbers are needed to simulate the random situation.
(3) we need to distinguish between different windows or different self service ticketing machines.
(4) receive service / self service tickets with a random number simulation time.)