Ive never understood the point of an OPC. Why on earth do companies develop company specific SOPs and not simply train people the way the manufacturer suggests. If all the companies that did that there wouldn't be a problem would there? If you don't like what the manufacturer suggests then feed it back to them for them to review and change - that way you get the feedback of lots of companies and better procedures.
Which SOP do you have in your company that is an improvement on what the manufacturer does?