Make sure you give the main auditee a heads up . Call a day or two ahead of time to confirm the audit schedule. In some cases a week might be more appropriate.
Ensure everything is on track
Are the auditee(s) aware of the need for them to be available?
Is the scope of the audit understood?
Is the expected length of the audit understood?
ISO 19011 - Quality and Environmental Management Systems Auditing Forum Discussions