How to count, examples, etc. For small company not more 10 people right now (designers, developers, managers).
Entreleadership: https://www.entreleadership.com
They use the term KRA for key results areas. Here's one reference from them but you should also browse around their blog and podcasts. There is a bunch of good information there.
https://www.entreleadership.com/videos/video-coaching-tip-of-the-day:-key-resul
Chris Locurto also has a bunch to say regarding KRAs: http://chrislocurto.com/?s=KRA
Hope that helps.