Morning Mad Max.
We have a schedule that entails a different section being audited per month. For the remaining months i then have other things such as policy review. This schedule also includes site hygiene, GMP, and all external audits and i refer to it daily so i can see how i can prepare for whats to come.
I think there should be many procedures in place daily that have to be validated somehow, which then confirm implementation of the program, could potentially identify gaps and should include employee audit readiness.
Definitely have independent internal auditors - the more eyes and minds the better for identifying gaps.
I'm positive i have an adequate internal audit schedule and several, several daily procedures that validate the implementation of policy, staff behavior etc. however i still sit here racking my brain about how i can find the non-conformance / compliance before an auditor!
My manager is annoyingly superb at playing devils advocate - so ensure you have someone who can challenge your every thought as this is great at bringing up potential holes and what ifs.
If you have a solid internal audit schedule, and are completing all kinds of audits to a good standard and genuinely implementing the corrective action (i know we sometimes don't) - then sometimes it is just a case of letting an auditor inform you through the means of non-conformances. Annoying, yes, but they are truly one step ahead of us all!
I also often find this site absolute gold for raising things i would have never thought of - maybe you could include a section for development and research?
I know this didn't given you a procedure that you asked for - but just thought i'd share my thoughts.