Plan-Do-Study-Act Cycle where did it come from?

November 11th, 2011

One of the world’s most popular problem-solving methods is the Plan-Do-Study-Act Cycle (PDSA) that has evolved throughout the decades. The Cycle can be summarised into four straightforward steps:

  1. Plan – Considering objective questions and predictions, as well as planning the who, what, where and when phase of the cycle
  2. Do – Putting the plan into action, as well as documenting any problems or uncertainties that may arise and begin to analyse data being gathered
  3. Study –  Completing the analysis of data, comparing data to predictions made and making a summary of what has been learned
  4. Act – Deciding what changes are to be made and whether to perform the next cycle

However, while popular the PDSA Cycle’s origins are rather complex. Created in the 1950s by W. Edwards Deming, the PDSA Cycle was inspired by other problem-solving theories including that of Galileo, the father of modern science and his contributions to science and motion and combining experiments and mathematics; Sir Francis Bacon and his philosophy of knowledge where it should follow a planned structure; and the theories of Charles Peirce and William James, Harvard graduates who were linked to the philosophy of pragmatism where the function of thought guides action and that truth is tested by practical consequences of belief.

Walter A. Shewart’s concept of specification production, devised in 1939, was also a great inspiration to W. Edwards Deming and led him to modify Shewart’s concept. Shewart used a straight-line and later a cyclical process with which to conduct a task and to acquire knowledge, starting with specification, to production and finally ending with inspection. Deming later built on Shewart’s concept in 1950 by emphasising the significance of the relationship between design, production, sales and research.

Later in 1950 after Deming’s presentation of the PDSA method, Maasaki Imai and other Japanese executives created their own method, the Plan-Do-Check-Act cycle that had some similarities with Deming’s earlier model, focusing on:

  1. Plan (Design) – Where product design relates to the planning phase of management
  2. Do (Production) – Production relates to the doing, making, working on the product being designed
  3. Check (Sales) – Where sales confirm whether the product is successful, confirming customer satisfaction
  4. Act (Research) – Should there be complaints about the product, it must be linked to the planning phase and action taken.

Deming later revised his PDSA Cycle in 1986, then 1991 and again in 1994 simply renaming each step as Plan, Do, Study and Act, as well as including a Model for Improvement focusing on  improving and accomplishing a task.

Although its foundations may be rooted in the intricate theories and ideas by some of the world’s greatest minds, variations through time now provides all workers with a problem-solving model in the form of the Plan-Do-Study-Act Cycle that follows an easy step-by-step process to perform tasks. Most importantly, this method of problem-solving also helps workers to remain safe in the workplace and to make logical and informed decisions before solving any problem.