I just got this achievement yesterday and the ONLY thing that counts are alarms set off by soldiers using control panels on the wall (they have hand icons on them), failing hacks, and by cameras spotting you.
I did this on my 2nd playthrough let me explain the things I did which still allowed me to get the achievement:
I murdered EVERYONE. Every mofo I came across. Seriously, doesn't matter if they spotted me and went hostile as long as I killed them before they touched the alarm on the wall. Doesn't matter if one of them came across a body and were "alerted" I killed them as well.
Many cameras spotted me and were "suspicious" but they didn't set off the alarm. If they turned red (or spotted a corpse) I would reload, but otherwise I moved on.
Turrets spotted me and beeped, but didn't raise the alarms.
I threw many EMP grenades at cameras and turrets to destroy them.
I disconnected a hack if I felt I was going to fail it. (failing a hack will set off the alarm).
I almost never got the "Smooth Operator" bonus.
I killed all the crazy people at Panchea.
I also triggered a lot of frag mines and threw frag grenades whenever I wanted.