Plan-Do-Check-Act and the grandfather of Total Quality Management

Zoe Marmara ⚡
2 min readSep 14, 2020


Apparently, the Plan-Do-Check-Act (PDCA) cycle is considered a project planning tool. It is also known as the Shewhart Cycle, as it was invented by the grandfather of Total Quality Management (TQM), Walter Shewhart.

The Plan-do-check-act Procedure

  1. Plan: Recognize an opportunity and plan a change.
  2. Do: Test the change. Carry out a small-scale study.
  3. Check: Review the test, analyze the results, and identify what you’ve learned.
  4. Act: Take action based on what you learned in the study step. If the change did not work, go through the cycle again with a different plan. If you were successful, incorporate what you learned from the test into wider changes. Use what you learned to plan new improvements, beginning the cycle again.

TQM is a system of management based on the principle that every member of staff must be committed to maintaining high standards of work in every aspect of a company’s operations.

The year 1924 saw the start of two of the most important developments ever in managerial thinking. In May that year Walter Shewhart described the first control chart which launched statistical process control and quality improvement. In November of that year there began a series of research projects which came to be known as the Hawthorne studies. Shewhart’s work specifically, control charts and the PDSA cycle influenced the daily work of quality extensively.

The Hawthorne studies are given their name from one of the most famous industrial history experiments that took place at Western Electric’s factory in the Hawthorne suburb of Chicago in the late 1920s and early 1930s. Walter Shewhart left Hawthorne in 1925.

Shewhart’s influence on ASQ runs deep. In the preface to his book “Economic Control of Quality of Manufactured Product” Shewhart stated:

The object of industry is to set up economic ways of satisfying human wants and in so doing to reduce everything possible to routines requiring a minimum amount of human effort. Through the use of the scientific method, extended to take account of modern statistical concepts, it has been found possible to set up limits within which the results of routine efforts must lie if they are to be economical. Deviations in the results of a routine process outside such limits indicate that the routine has broken down and will no longer be economical until the cause of trouble is removed.”

More on Walter Shewhart:



Zoe Marmara ⚡

Product Owner by day, wordsmith by night. 🚀 Exploring tech, embracing growth, and sharing laughs along the way. 🌱✨ Join me in this joyful journey! 💪