排队论中可以按指数分布的时间间隔产生一个队列，并进入服务时间服从指数分布的服务台，画图得出其到达时间与离开时间，还有每个顾客在系统中的逗留时间(Can produce a queue according to the time interval of exponential distribution in queuing theory, and enter the Business Hours exponentially distributed service station, drawing the arrival time and departure time, and each customer in the system of the sojourn time)