Agree with WODRICK, starting was straightforward.
Maybe SOPS is referring to the change over from APU bleed air to engine bleed air after take off when a correct sequence of valve opening and closing was required.
I seem to remember there was a story about a British Eagle One Eleven that stuffed up the sequence and left the APU bleed on mixing with the engine bleed. After about an hour they had a serious duct over heat problem.