Dr. Deming was amazing, but who was his teacher? Who produced the PDCA Cycle? Who conceived of Statistical Process Control? The modest man behind the scenes, another fascinating product of the Hawthorne Works, was none other than Walter Shewhart.
This year would have marked Walter Shewhart’s 126th birthday – truly a Great Grand-Daddy of Quality. Born in Illinois, Mr. Shewhart was a physicist, engineer and a statistician known primarily as the Father of Statistical Quality Control.
Claims to Fame – What Did He Invent?
Statistical Quality Control:
Statistical Quality Control ensured product consistency.
Walter Shewhart was a modest man, but he was a true pioneer. He found a way to measure and improve process consistency. That may sound mundane now, but back when Mr. Shewhart was at Bell Labs this was a big deal. He was focused on the idea that processes had to be predictable in order to consistently make money for the company.
He worked on improving voice quality over the phone lines. Instead of getting on a call line and asking, “can you hear me now?” he separated the results of the process into two categories:
- Predictable – Some things happened on calls all the time. Low voices were hard to hear, the longer the distance the lower the quality or maybe the thickness of the wires made a difference – just “common stuff”
- Unpredictable – Some things didn’t happen too often. Heavy ice in a snowstorm might cut out voices entirely, or lines too near bridges might turn a call to static – we’ll call this “special stuff”
He determined that if a process could remove, prevent or mitigate the “unpredictable” stuff, then it could be controlled. The only way to consistently meet customer requirements – “yes – I can hear you now!” – is to have a predictable, controlled process.
His Control Charts determined whether processes were predictable or not.
The way Dr. Shewhart determined if a process suffered from “special stuff” – technically “special cause variation,” was to invent a simple diagram known as the Control Chart. His modest drawing, among other things, spawned an entire industry of statistical software packages. These charts made it easy to see if something was going on in the process beyond common cause variation. They signal special cause variation as you can see in the Control Chart below:
His charts are in used today in every in every process and industry you can think of – what a gift!
Little Known Facts:
- He worked for Bell Telephone Laboratories for 31 years
- He was Dr. Edward Deming’s mentor – another Quality Guru!
Walter Shewhart at the Bahama Bistro:
Quote of the Day:
“Shew-hart? What exactly is the heart of a shoe? The Soul!”
Putting Walter Shewhart into Action:
- “We tracked lunch delivery time with a Control Chart”
- “We’re in control – Walter would be proud!”
Walter Shewhart was not only a quality pioneer, he was a mentor to another beloved Quality guru, Dr. Edwards Deming. The two of them enjoyed a decades-long collaboration and created what is now known as PDCA (Plan Do Change Adjust/Act) was originally known as the “Shewhart Cycle.” Deming tried to honor his mentor by naming his technique for quick improvement cycles. Along with Control Charts, PDCA lives on.