Short for "Pain In the Ass Factor", a measure of how irritating a particular person, job or activity will be. Often encountered in the IT world. Sometimes stated with a numerical range, such as "A PITA Factor of 100".
It's not hard to replace a a user's computer, but migrating over all their old stuff has a high PITA Factor.
pain in the ass factor....on a scale from one to ten.
I hate dealing with that sales rep.,his pita factor is a ten.