Hi,

I know control limits are based on the project quality metrics and specification limits are based on customer input?inherent in the process.

So the control limits are to be stricter than specification limits.So does that mean if spec. limits are 3 sigma customer should be 6 sigma.

I cant relate this on the control chart as spec limit line is outside the control limit.
So can 3 sigma line be outside 6 sigma line??