Re: SPC for Dummies
We currently track individual measurements by cavity in a program called QcCalc. I'd like to group the cavities (say a 6 cavity mold) and XBar R chart the single shot of 6 Cavities. 16 would be the maximum amount for any group.
Before you do that you need a convincing argument that the variation
between cavities is
statistically insignificant, so that when you are analyzing your variation and out of control events, you know that it is a process issue (material, pressure, temperature, humidity, etc.), and
not a cavity issue, flow or mold issue, and can respond accordingly.
Of course, if your molds are
that good, why not just do one cavity? Feeling lucky?
Some short cuts never get you to where you were trying to go the long way...