Okay, let's say you are a small stamper (25 employees). You stamp blanks. Your dies are customer supplied, as is your steel. All of your process are pretty much straight forward and simple. What's there to audit? You've got a mature system (all of the bugs are worked out), you're following your processes, major changes are rare.
I have a difficult time understanding why you would have to audit monthly, unless you have a very complex system, or there are a lot of changes.
I was at a place last month that had a brand new QMS (didn't have one before). They had a whole bunch of different processes (stamping, bending, welding, painting, sewing, etc.). Despite the different processes, each process was being performed consistently within the rules they established. I found nothing that would make me want to audit them monthly (or even quarterly), if I were their internal auditor. Did I find things? Yes. But even with the stuff I found, there was nothing that would make me feel that the process "status" requires more frequent auditing.