'Dag, Mijn heer!
I agree that you should keep management involved, but it sounds to me that you should change your procedure! Incidently, an effective audit procedure shouldn't define audits by 'department' and certainly not 'every department'!! The ISO 9001:2000 requirements indicate that 'processes' should be audited.
My approach to auditing management is to find out how their processes are performing, say late delivery, scrap rates, poor supplier performance, inventory turns, etc and then audit the process to find out why these things are happening. You could involve them in the audit planning process to see if they have any reasons for 'loosing sleep' over the process. Or, you could ask what's new or changed in the process to see if the change is under control!
I hope this helps. I will be pleased to give you more if you need to. Tot ziens, Gaby!
Andy