Let's see.....things outside of my control:

equipment operators

machine programming/design

quality of the parts

the mail being run through the machines.

Extra time spent outside of work: about 2 years training (so far) in Oklahoma away from home, in addition to the training and experience that got me the job in the first place, and occasionally fielding calls to help other techs when things really get screwed up.

I still get paid if I can't fix a machine or a network system, but if it happens too many times I'll have issues.

We all deal with issues in our jobs which are outside of our direct control. No one profession has a corner on the work done behind the scenes.