BW建模：
https://help.sap.com/saphelp_nw73/helpdata/en/e1/5282890fb846899182bc1136918459/frameset.htm
http://www.sapzh.com/html/sappress/375.html
https://archive.sap.com/documents/docs/DOC-59790
https://blogs.sap.com/2012/05/04/sap-how-to-guides-for-sap-business-warehouse-powered-by-sap-hana/