Re: SPC vs. 100% Inspection - Is SPC still value-added when 100% inspection is in pla
I am anti-100% inspection, well nearly. Fast pace automation with inspection with laser, camera, CMM, vision coordinate are essential at times.
In other cases, if I was a customer or the producer, or like in most cases, the consultant, my question is why is there so much effort on inspection? I am led to believe there is high variation an inadequate controls for producing a good part. In nearly every time I have consulted or observed 100% inspection, there is little QC inline and upfront, out side of the inspection. Inspection is not quality control, it is just inspection.
100% is less effective and efficient then the alternative of SPC with better processes. Better processes = better parts = less wasted labour = more time and energy to spend improving the processes.
Find your industries specific stats, your in-house specifics, and challenges; then attack with a well thought out SPC. You can start aggressive for frequency and then back off when all is proven with preventative measures in place. Use the PDCA cycle. That, in my experience has always been a winner and brought true quality control to processes-- with evidence.
Do that, and Juran would be proud.
Such an approach is bigger in scope, but far more rewarding.