2.2.1Statistics of basic business
There is a great variation of the number of customers’ arrival in different time period. Meanwhile,different business has different handling time. Aiming at this situation, here’s the mean of the two-day’ 642 Tian Haoa and Tong Yifei / Procedia Environmental Sciences 10 ( 2011 ) 640 – 646 statistics (Tuesday, Friday).We divide the serving time into four parts. In each part, we divide the business into three categories: Saving business, corporate business and VIP business. Statistics is listed in table1.