One cycle to inspire them all

I have worked in lean or agile teams for a number of years and developing my knowledge of lean and agile has helped me. The Deming Cycle is something I have found helpful to understand because it is a part of agile and lean and it is also about continuous improvement of quality.

Engineering teams have been using the cycle to improve the quality of their work for nearly one hundred years so I expect to be using the cycle for the rest of my career.

W. Edwards Deming learnt the cycle from Walter Shewhart. When Deming was working to help rebuild Japan after World War Two he presented the cycle as the Shewhart Cycle but it went into use as the Deming Cycle.

There are four parts to the cycle:

• Plan – plan what the team will do
• Do – build and test
• Study –  What was wrong? What was right?
• Act – change the way of working based on real results

The cycle is repeated and the team moves forward with the knowledge they have accumulated.

The reason to study is to learn how to improve tomorrow’s product. Everyone can take part and everyone can contribute ideas.

The diagram above shows all four parts of the cycle in a circle, so are all related to one another and there is no hierarchy. 

Deming spoke about the cycle as a wheel that rolls along the line of “concepts regarding product quality” and the “sense of responsibility for product quality”. He also wrote about it under “continuous improvement of quality”.

The Deming Cycle has influenced cycles used in engineering. In “The Toyota Way” Jeffrey Liker said that it embodies the learning cycle in the Toyota Production System, and in this way it is part of Lean. In “The Art of Doing Twice the Work in Half the Time” Jeff Sutherland says that “it’s how… Scrum product development is done”, and this is a way that it is part of Agile. Other cycles can also be seen to have been influenced by the Deming Cycle.

It is helpful for us as testing professionals to understand the Deming Cycle because we mostly work in lean or agile teams and we want to improve quality.

Further reading: 

• The PDSA Cycle
• Out of the Crisis by W. Edwards Deming

Further viewing (you can log in and view the video for free):

• What did Deming’s work on quality do for us?

eLearning:

• DemingNext