Need Advice on Quality Control and Process

I have recently been placed in our printing plant as the Quality Control Manager. I have worked in the bindery for three years but other than that I have very little experience in printing. At this time the pressmen do their own quality checks and we have no procedures in place. I have been asked to create them.

How often should an operator be pulling sheets to check the quality? When press-sheets are pulled, should we save them with for a period of time?

Any advice with checklist or procedures on quality would be greatly appreciated. We run two shifts with 4 sheet feeds presses, a web press along with a fully operating bindery.


Thanks
Inhouse Printer