Hi JayaSantoshKumar,
Yes, if you want 8 hours to 0, you need to set 0 in adjustment timesheet.
If your PPM is old version (maybe 12.x ), you may be able to remove timesheet entry in adjustment timesheet.
If you remove timesheet entry, it does not mean 0 hours. It is not a correct operation to change it 0 hours.
I experienced that some user used to remove timesheet entry in adjustment timesheet to change actual hours to 0.
After post timesheet, actual hour will not be 0 hours. Previous hour is still remained.
If user wants to change it to 0 hours, user must set 0 hour in adjustment timesheet explicitly.
It often confused user.
The Delete button in adjustment timesheet is removed from 13.x version.
I think it is enhancement to avoid miss-operation.
Regards,
Shoichi