When you install BI Applications, you install source files in the BI_Oracle_Home/biapps/etl directory. Functional developers configure these files for use during the ETL process. You must copy these files to a location that the ODI Agent that is deployed in the Oracle WebLogic Server can access but that is outside of the Oracle Home directory. If you don't copy the files outside of the Oracle Home directory, then when you upgrade or patch BI Applications, the files are overwritten.