Lot of folks have tried to implement the PR Approval at header level using Approve Requests and now there Fiori App for this is available out of the box: Check it out @
http://help.sap.com/saphelp_fiori_erp_100/helpdata/en/b3/f03a5225ecbb10e10000000a44176d/content.htm?...
This Fiori App can now approve at Header + Item Level of PR i.e Overall Release as well as approval @ line item level. This is really cool.
Lot of extensibility options are there too.
App Extensibility: Approve Requisitions - SAP Fiori for SAP ERP 1.0 - SAP Library
Thanks
Ashish
