Hi Raman,
Firstly, I checked program in the display message on right click the process chain step, and the chain is in the prd environment. I also check the program variants in the prd env. So it shouldn't has a system conistency problem.
Then I checked VARID in se11, ZRPR021_V03 isn't in it.
I'm not familiar with abap. So here is a simple question I want to solve……"How to know where does the program use the variant?"
I think that may be the variant doesn't have any duty in the program.