Please bookmark this link which gives the list of new/incremental functionalities tested & QA-ed for every Oracle release from Oracle 11.5.10 . Scroll down to the end and click on attachments to view the exact HCM functionalities in that version. In case of upgrade projects it maybe simply sufficient to test and analyze these new functionalities on the seeded Oracle instance.
The metalink Document ID is : 1113083.1
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=1113083.1
Other useful upgrade project links :
Oracle E-Business Suite Release 12.0 Information Center - Documentation [ID 790190.1]
https://support.oracle.com/CSP/ui/flash.html#tab=KBHome(page=KBHome&id=()),(page=KBNavigator&id=(bmDocDsrc=KB&bmDocType=BULLETIN&bmDocID=790190.1&viewingMode=1143&from=BOOKMARK&bmDocTitle=Oracle%20E-Business%20Suite%20Release%2012.0%20Information%20Center%20-%20Documentation))
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=394692.1
Oracle HRMS Documentation Resources, Release 12 [ID 395405.1]
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=395405.1
Oracle Applications Documentation
http://www.oracle.com/technetwork/documentation/applications-167706.html
All documentation http://tahiti.oracle.com/
List of API's :
http://irep.oracle.com
Vision Demo Document Index (Procurement) [ID 1075748.1]
E-Business Suite HCM R12.1 Information Center [ID 1100428.1]
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=1100428.1
QA Testing Approach and Features Tested for Oracle HRMS - Archive [ID 1113083.1]
https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=1113083.1
