Absolutely Everyone whose job affects quality is subject to the audit. Which is to say Everyone!
And the farther up the corporate tree you go, the more difficult the audit is. This is because as you go up the tree (eventually to the plant manager), job duties and responsibilities increase.
Corporate Personnel
Plant Manager
Departmental managers
Supervisors
Engineers
Technical personnel
Hourly employees
ISO 19011 - Quality and Environmental Management Systems Auditing Forum Discussions