The best part of the job is that you get to be a kind of detective who solves mysteries of problems that arise on the production line. Most of the time, problems aren’t what they appear to be at the surface, and to solve them permanently usually involves in-depth technical analysis, talking to lots of people, reviewing product history and documentation and more. The worst part is writing up the supporting documentation that defines the changes that solve the problem. It's more fun to solve the problems than it is to write about them after they have been solved.