Operation Improvement Inc.

“You can’t inspect quality into the product! Quality begins in the process.”

I’ll never forget the night a glass tabletop in our home suddenly exploded – shattering into an uncountable number of tiny pieces. It had not been struck, abused, or even touched. There was nothing on the tabletop, and the glass had been resting gently on several rubber supports for months, possibly years.

Why Spontaneous Explosion Occurs to Tempered Glass – LandGlass
(Why Spontaneous Glass Explosion Occurs)

Without any evidence of defects or non-conformities of any kind, this shattering event was likely born in the -process- which created it. But can product inspection tell us things about the temperature or pressure differentials when the glass tabletop was created? Most often, it cannot.

Perhaps there are exotic techniques that can extrapolate these facts; but once the product is formed, the opportunity to measure and to know is lost.

Remember that SPC is Statistical –Process– Control? Metrics of process are just as important, and sometimes more important than finished product dimensions, weights, colors, and tolerances.

A real-time product metric does have some ability to “look back” into the process and we can infer process consistency to an extent. Time series temperatures, processing speeds, and other measures of activity provide that direct look many operations want and need.

Whether it is food prep in the kitchen, pouring and curing concrete, or making tempered glass – process metrics tell an important part of the Quality story that product inspection alone cannot.