Auditing can be seen as a fairly negative process, with the emphasis being on digging into the detail and raising what is seen to many as trivial issues.
Consequently, when selecting internal auditors it is normal to add more junior staff to complement the small team of quality, environmental and health & safety professionals.
Internal auditing should be focused on improving the management system, and hence business performance, and therefore more senior managers should be involved in internal auditing.
One of the ways to get them involved is to allocate to them the task of auditing for improvement, with more junior staff involved in the more time consuming tasks of conformance auditing.