PDSA - A Flow Diagram for Learning!

As a Toyota Team Member I have spent my career learning and using PDCA, and in my classes on Scrum The Toyota Way and in the development of The Toyota Flow System I go back into the history of its development stemming from the work of Walter A. Shewhart, Deming's mentor and teacher.

Deming always credited Shewhart with what many call the Deming Wheel (PDSA), which started its life as the Shewhart cycle 'Specification, Production, Inspection', and while we all know PDSA and the Toyota derivative PDCA as a quality tool, and sometimes a problem solving approach, it was actually described by Deming as "A flow diagram for learning".

A Flow Diagram for Learning!

That is an incredibly powerful description. MVP anyone? Iterative empirical planning and development? And as he describes in the video, "preferably on a small scale". Short Sprints? Small batch production?

It's all about planning. People need to learn to plan. Scrum is also described by Ken Schwaber as 'a planning cadence' (source: Dave West Scrum Org).

I was recently gifted a video of Deming describing PDSA. I would post it here, but I am unsure of the copyright holder, so instead here is a screen cap and the transcript of his explanation. PDSA in Deming's own words.

"The PDSA cycle is a flow diagram for learning. 

The first step is PLAN. The first step is ideas in peoples heads. About improvement, or innovation, new methods, or comparisons of methods. 

Step 2 DO IT. Carry out the test, comparison or experiment, preferably on a small scale. According to the layout decided in step one. 

Step 3 STUDY. Study the results. Do they correspond to the hopes and expectations? If not what went wrong? 

And finally ACT.

What do we mean by act? We mean adopt the change, or abandon it, or run thought the cycle again. Possibly under different environmental conditions. I’d say certainly under different environmental conditions, different materials, different people. See if we get anything like the same result. Maybe make some small changes in the rules."

Deming Goes to Japan

My thanks to my friend Charlie Protzman III for giving me access to the source, and for his invaluable teaching and learning as we continue to evolve our own thinking. His anecdotes and archives are a source of immense historical value.

Who was Homer Sarasohn and Charles W. Protzman?

In early 1946 Gen. Douglas MacArthur asked a radio engineer named Homer Sarasohn to go to Japan to help rebuild the country’s war-torn radio industry. Charles Protzman Sr arrived to help Sarasohn in 1948, Protzman had been charged with running Japan's telephone system, and together they prepared the textbook, The Fundamentals of Industrial Management, written by Sarasohn and Charles W. Protzman, Sr., in 1949, used by Sarasohn in his training courses for Japanese manufacturing executives. (Source: Library of Congress). This book is still in print in Japan!

Image: Charles W. Protzman and Homer Sarasohn (2nd row 1st and 2nd from right) in 1948 Japan.

To quote Sarasohn in a paper he wrote in 1998 on the course they developed together.

"A colleague of mine in CCS, Charles Protzman (now deceased), and I decided that a university– level course in the fundamentals of industrial management was needed to modernize the practice of management in the communications industry. The course would be called the CCS Management Seminar. Senior executives of the companies in the industry would be obliged to attend as students. Protzman and I would be the teachers. We would write the textbook since none other existed that met our requirements. Protzman’s half of the book had to do with the pragmatics of manufacturing: industrial engineering, production processes, cost controls, plan layout, etc. My part covered management policy formulation, strategic planning, organization principles, product innovation, quality control, etc."

When they returned to the United States, Sarasohn recommended Deming to continue the campaign of quality that he and Protzman had begun. Charlie's grandfather and namesake worked with Shewhart and Deming and he tells me that Shewhart was Sarasohn's first choice to go to Japan, but due to ill health could not go. Charlie's grandfather encouraged Deming to go instead, and the rest, as the say, is history!

Quoting Sarasohn from a PBS documentary 'I, Cringely . The Pulpit . Stranger in a Strange Land | PBS'

"Deming was actually our second choice," Sarasohn recalled. "We wanted Walter Shewart from AT&T Bell Labs to be our quality guru, because he virtually invented statistical quality control in the 1930s, but Shewart wasn't available at the time — he was in poor health — so we settled for Deming."

I am so damn lucky to know the people I know!