My thoughts
Based on the information I was given by IO today and further research online, I guess this is how USCIS process our petitions. Please check the link at the end of my message
1) Applicant mails petition to lockbox (maintained by a private contractor)
2) Private contractor determines the basic eligibility of the applicant to file the petition, cashes the check and does data entry
3) NBC takes over, does preliminary review, creates T-file (temporary file), prints case receipt for applicant
4) NBC send RFE to applicant if any additional documents are needed
5) NBC orders FP notice
6) Applicant finishes FP and it goes to FBI
7) FBI sends feedback to NBC
8) NBC requests A# file from “SOME” location
9) NBC simultaneously prints the check list and mail it to applicant for advance interview preparation (this step is not particularly fixed)
10) NBC receives A# file from the location where our A# file is currently sitting
11) NBC merges T# file with A# file, does one final review of the application to make sure everything is in order including FBI feedback
12) NBC then puts A# file in the SCHEDULING QUEUE for the corresponding DO we come under (this is a systems communication from NBC to local DO that this guy’s file is ready for interview now)
13) Depending on the work load, the local DO people will access the queue and determines the interview date and time and approves it. That’s why some DO’s are faster in IL scheduling than other. Local DO’s with larger immigrant population tend to be slow compared with other DO’s who see very few petitions a month.
14) NBC prints the IL and mail it to the applicant
15) NBC simultaneously mails the A# file physically to the local DO, in time for the interview
16) Applicant receives the IL and goes for the interview
I guess I am stuck at level 8. Also, check this out
http://www.usa-immigration-law.com/uploads/NBC_Issues.pdf