Follow the process from : http://docs.ofbiz.org/display/OFBENDUSER/Receive+Purchase+Order
Followed process mention with issue and Implemented test case for issue
In which assert tag is used to test desired output .
Thanks to Ratnesh Upadhayay for their help.
Thanks and Regards
Automated Test Case "testWarehouseManagerRole"
Created Purchase order data ans Shipment data for the automation.