AIX

I would like to ask for you suggestions or comments see if you can help.
Since system auditing is under progress and the AIX is the main
investigated unit. They are asking to disable the FTP service to enhance
the security but I doubt. For daily use, the FTP will help administrator
to download logs--daily performance log (the nmon I talked to u before),
download and upload scripts, and also upload the unix programs. I am not
experted in unix but based on your experience, do you think if there's
any other better ways to perform the above tasks. If possible pls advice
any article or comments about this issue....I don't think too harsh is
the best...Thanks very much!

Security is correct in telling you to disable ftp. If you use ftp, you are sending the password in clear text over your network and that password could be easily intercepted.
A solution that many people use is sftp, which is part of the ssh server.