I agree with xx-Nepal rather than Dhoti Prasad. THe mail point I disagree with Dhoti prasad is,

For PERM also the employee's information is required so How can the employer approve PERM for one person and can hire another

person with the sampe PERM approved for previous person.

My question do one have to attend the interview for I-140 and I485 approval?

By the way how long it will take to complete the process if the filing is done separately. I mean first only I-140 and after approval of that I-485?

I appreciate your suggestions.