So help us out...what is your objective? It will, IMHO, be no 'small effort' but will make a 'rod for your back' to try to develop such indicators. It sounds to me as if your management don't want to invest in internal audits. Have the auditors already had class time? What are you seeking to accomplish with more class time? If you find the root of the issue it'll be better to address that - if management don't support IA, then THAT's what you must address - and we can help you!!
for pharma industry where i am working, Internal audit is often/always a matter of "regulatory audit-compliance"...Its not that often to be used a tool to drive improvement!.
Parallelly, I was trying to device a way through improvising the system. such that it demonstrates the "state of affairs + probably provide an target/objective to the internal auditor". Yes i take the caution that checklist will only help as much as the skill of auditor...but that is minimum starting point for aiding as pointers to SOP(aiding auditor-memory.
+ when we start measuring with above indicated metrics, we could reflect on the areas of improvements OR provide a basis for telling management to act(invest) in people training.
in short, my objective of posting above concern...
1) share my approach on improving "internal-audit-objectivity/effectiveness"
2) take your feedback on possible metrics
3) find out any better/simpler ways of doing it
thank you all for your patience