Would starting a regular auditing system where we systematically go through the AIs to verify accuracy be a sufficient preventative action?
Actually I'm not sure what the current preventative action is, because just fixing all of them sounds like a corrective action to me. I'll find out more this afternoon.
Then comes into question the effectiveness check. Currently the effectiveness check is an audit (sample) which includes observing an employee to see if they follow the exact order of the procedure. ....
Keeping in mind that you said earlier you've not had any issues historically...pick the simplest way possible.
Call it CA, call it PA...call it continual improvement...call it George...can't see that it matters.
Effectiveness? Identify the single largest motivational factor for undertaking this huge effort...and measure effectiveness against that.
From the full chain above, it sounds like the main impetus is "Bob wants it".
The effectiveness check will be "Bob is happy". (worded all quality-like, though)
I would likely chalk this up to continual improvement.
For a CA, you (sorta) need a non-conformance that already happened, and it doesn't sound like that exists.