Which job is more functional? 1. Customer Service 2. Administration 3. Documentation 4. Eventmanagement 5. Teaching

All options.

Every action has its characteristics 

From my point of view the whole work is important

i think all of them

Akk of them require mucg funcionality, so how can we say more this or less that?

ALL

I think Administration's job is more functional. 

All-important. Can not be a trade-off between them.

Administration.

Each of these jobs functions has its own value and importance’s.  NO jobs are big or small, job is job!