Changing a job, how is the visa process?

I live in Shanghai for a year and half and thinking of changing a working place.
So when I change a work, I have to get a new Z type, but do I start over from which steps? from very very begining?
Honestly, our campany made some arrangement on my resume, to make sure I can obtain Z type. Does it affect to new Z type or it will be a problem?
I am a Japanese passport holder.