Hello Krishnendu,
Interesting to know why you need this 
.
The only way I believe you can obtain this information is by going through the release notes across various SAP releases available on service market place (SMP).
I saw the release notes for SAP release 46A, and I can see all 3 PP-PI, PP-REM and PP-Discrete processes, the functionality in each of the process has been added over the years, example Xsteps was added in SAP R/3 Enterprise Release 470x200.
http://service.sap.com/releasenotes
I hope below images help you navigate in release notes (You need to be having a valid SMP login).
Best Regards,
Ameya Beri