David Hutchins

The PDCA Cycle (Plan, Do, Check, Act Cycle was originally articulated by Dr Walter Shewhart . His monumental work, Economic Control of Quality of Manufactured Product, published in 1931, is regarded as a complete and thorough exposition of the basic principles of quality control. Whilst Deming is frequently and mistakenly accredited  with the concept. its use was widespread even with all of its variants, long before Deming. This is true for the  PDCA/PDSA Cycle in particular because, even  Shewhart would be just a little behind history if he were to have claimed that he actually invented the concept.  I do not believe however, that he did make any such claim, I think he was actually quite a modest man. Shewhart was a biologist and a statistician before joining Bell Telephones as an Executive. Biology was more or less the birthplace of Applied Statistics  and long before Shewhart joined Bell, a magazine Biometrica had enunciated the principles of ‘Control’. In reality the origins of the principle Plan, Do, Check, Act are lost in history and can be traced back to at least  the 13th Century. However,  it could be argued that it dates back even further, to Aristotle. It was very well understood by Newcomen and Watt and the ‘Porter Speed Governor’ worked on this principle. Other pioneers of the industrial revolution were also aware of it so by the time the then 50 year old Deming included it in his lectures it was hardly hot news even to the Japanese who had Statistical Quality Control even before WW2. However, in those early days, the concept was more associated with mechanical feedback systems rather than man/management models. Actually, credit should really go to Professor Ishikawa for taking the concept which was until his time, a systems tool rather than a behavioural one and using it to describe the nature of differing types of human relationship in organisations.

For example, shown here (extract from DHIQC Student Notes for U301 and U501 People in Quality Unit) as a graphic means of describing Taylor style management.

Post Taylorism

However, even there, one should not overlook Dr Juran’s variation when describing work itself. Juran described the circumstances that must be in place in order that the worker was in a situation of having control over his work.

First of all he needed to know what was expected of him (Plan),

Have the means to do good work (Do)

The means to check his own work (Check)


The means to take corrective Action if the work was not in accordance with the instructions. Juran said, that if any of these elements were not present, then the manager’s job was incomplete and any resulting defects or deficiencies were managements responsibility not the workers because the management job was incomplete.

All of this was included in Dr Juran’s massive tome, the Quality Control Handbook first published in 1951 but it must have taken him many years of research in order to assemble that huge quantity of material. Ishikawa took this idea further and used it to describe the Man/Management relationships of different styles of Management.

The diagram above shows that in a Quality Circles based management , the foreman is the link between the workforce and management. In this model the foreman is very highly respected by both management and the worker. By management because he is the person who gets things done and by the workforce because of his skills and know how.

Note on the above diagram the role of specialists As industrial legislation has become more complex the scope of the manager has become hopelessly complex. Instead of involving the workforce, specialists have evolved to take over the process of dealing with these matters. In the age of Craftsmanship this would have been carried out by the supervisor and the workforce or craftsmen. Today, we have specialist personnel management or HR, Health and Safety, Industrial engineering, training managers, cost accounting, quality control, quality assurance, production control, scheduling etc. all of which were at one time the responsibility of the supervisor. As this process has continued, the role of the supervisor has diminished to the point where he simply hands out job tickets and acts as the eyes and ears for all of these functions but he is no longer responsible for them! Notice also the arrows leading out from the specialist. They show that the specialist acts as a consultant to both line and upper management and also the workforce through the foreman.  Some aspects of this are beneficial both to the organisation as a whole and to the individual. The specialist has company wide responsibilities and does not relate directly to any specific group of workers or to individuals other than in their own reporting hierarchy. All of the disadvantages of Taylorism were apparent to Professor Ishikawa in the late 1950s and he illustrated it using the PDCA Cycle! There were strikes, lockouts and at one point the country was on the verge of a communist revolution.

Professor Ishikawa said, this is because we have taken the American system of management, we have not considered its relevance to our culture and whilst it is very powerful, it cannot work as it is in our societies either. Actually we at DHI do not believe that in its pure form it can work in any society because the flaws hopefully discovered by you in the previous assignment are universal and not confined to just one particular race of people. Professor Ishikawa then said. We must create a new system, one which contains all of the benefits of Craftsmanship and all of the benefits of Taylorism but neither of their disadvantages ! He said that to do this, the division of labour concept must be included because from a productivity point of view it is just too powerful. We must also re-introduce Craftsmanship but how to do this? Professor Ishikawa said, maybe we cannot reintroduce it to individuals but possibly we can to groups of people.  This is the essence of Quality Circles. Most Western people think that Quality Circles are just small problem solving teams but this misses the whole point. It is to reintroduce the Craftsman concept! This is the essence of Quality Circles and Kaizen and the diagram shows this clearly.