Our site got audited a few weeks ago. Got a Non-conformance on SQF Quality Code 126.96.36.199 Verification activities shall include a comparison of process control limits (+/- 3 deviations) with specification limits to ensure alignment and appropriate process control. I have tried researching about SPC online, but couldn't find find much information as how SQF require to use SPC. Not quite sure what I need to do to fix this non-conformance. Can anyone give me an idea?