i have worked for 3 big big hi-tech companies and one cannot
avoid the annoying performance review. some call it performance
appraisal, etc. some have it once a year and some every 6 mths.

here are the usual things that always apprear on the review.

1) productivity & quality
2) planning & scheduling
3) skills
4) documentation
5) problem solving
6) communication skills
7) teamwork
8) initiative

as u can see, some are related to your skills and some are people skills.
that means, it's not only what u do but who u are that matters also.

things like;
how do you manage your project.
how do you deal with the planning and scheduling.
how do u deal with the project manager, your team-mates and your clients.

when u have your own business, u need to have a better people skills.