Dear Sekar,
First and foremost please understand that there is a difference between Performance Management System (PMS) and Performance Appraisal (PA). Former is far wider and latter is part of it.
Scores of times I have given replies on this subject. You can refer my following links:
PMS for workers
KRA Consultants
KRA sheet
KRA sheet
(last two links appear same but practically there are different)
Thanks,
Dinesh V Divekar