How to reduce OS booting time

I am using Red Hat Enterprise Linux 6.5 OS. It takes more than 1 minute for booting. I have already disabled services like network manager, bluetooth services,pcscd,mdmonitor. Our OS need to support to run minicom,touch driver and Qt application during startup. And also bootup time to be within 30 seconds.
So Let me know what all other unwanted services need to be disabled to speed up the booting process.

Hereby I attached the ps log for your information.
thanks.