PDCA (plan–do–check–act or plan–do–check–adjust) is an
iterative design
Iterative design is a design methodology based on a cyclic process of prototyping, testing, analyzing, and refining a product or process. Based on the results of testing the most recent iteration of a design, changes and refinements are made. Th ...
and management method used in business for the control and continual improvement of processes and products. It is also known as the
Shewhart cycle, or the control circle/cycle. Another version of this PDCA cycle is OPDCA. The added "O" stands for ''observation'' or as some versions say: "Observe the current condition." This emphasis on observation and current condition has currency with the literature on
lean manufacturing
Lean manufacturing is a production method aimed primarily at reducing times within the production system as well as response times from suppliers and to customers. It is closely related to another concept called just-in-time manufacturing ( ...
and the
Toyota Production System
The Toyota Production System (TPS) is an integrated socio-technical system, developed by Toyota, that comprises its management philosophy and practices. The TPS is a management system that organizes manufacturing and logistics for the automobile ma ...
.
The PDCA cycle, with Ishikawa's changes, can be traced back to S. Mizuno of the
Tokyo Institute of Technology
is a national research university located in Greater Tokyo Area, Japan. Tokyo Tech is the largest institution for higher education in Japan dedicated to science and technology, one of first five Designated National University and selected as ...
in 1959.
PDCA is often confused with PDSA (Plan-Do-Study-Act).
Dr. W. Edwards Deming emphasized the PDSA Cycle, not the PDCA Cycle, with a third step emphasis on Study (S), not Check (C). Dr. Deming found that the focus on Check is more about the implementation of a change, with success or failure. His focus was on predicting the results of an improvement effort, studying the actual results, and comparing them to possibly revise the theory.
Meaning
Plan
Establish objectives and processes required to deliver the desired results.
Do
Carry out the objectives from the previous step.
Check
During the check phase, the data and results gathered from the do phase are evaluated. Data is compared to the expected outcomes to see many similarities and differences. The testing process is also evaluated to see if there were any changes from the original test created during the planning phase. If the data is placed in a chart it can make it easier to see any trends if the PDCA cycle is conducted multiple times. This helps to see what changes work better than others and if said changes can be improved as well.
Example:
Gap analysis
In management literature, gap analysis involves the comparison of actual performance with potential or desired performance. If an organization does not make the best use of current resources, or forgoes investment in capital or technology, it m ...
, or
Appraisals.
Act
Also called "Adjust", this act phase is where a process is improved. Records from the "do" and "check" phases help identify issues with the process. These issues may include problems, non-conformities, opportunities for improvement, inefficiencies, and other issues that result in outcomes that are evidently less-than-optimal. Root causes of such issues are investigated, found, and eliminated by modifying the process. Risk is re-evaluated. At the end of the actions in this phase, the process has better instructions, standards, or goals. Planning for the next cycle can proceed with a better baseline. Work in the next do phase should not create a recurrence of the identified issues; if it does, then the action was not effective.
About
PDCA is associated with
W. Edwards Deming
William Edwards Deming (October 14, 1900 – December 20, 1993) was an American engineer, statistician, professor, author, lecturer, and management consultant. Educated initially as an electrical engineer and later specializing in mathematical ...
, who is considered by many to be the father of modern
quality control
Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements".
This approach places ...
; however, he used PDSA (Plan-Do-Study-Act) and referred to it as the "Shewhart cycle". Later in Deming's career, he modified PDCA to "Plan, Do, Study, Act" (PDSA) because he felt that "check" emphasized inspection over analysis. The PDSA cycle was used to create the model of know-how transfer process, and other models.
The concept of PDCA is based on the
scientific method
The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...
, as developed from the work of
Francis Bacon
Francis Bacon, 1st Viscount St Alban (; 22 January 1561 – 9 April 1626), also known as Lord Verulam, was an English philosopher and statesman who served as Attorney General and Lord Chancellor of England. Bacon led the advancement of both ...
(''
Novum Organum
The ''Novum Organum'', fully ''Novum Organum, sive Indicia Vera de Interpretatione Naturae'' ("New organon, or true directions concerning the interpretation of nature") or ''Instaurationis Magnae, Pars II'' ("Part II of The Great Instauration ...
'', 1620). The scientific method can be written as "hypothesis–experiment–evaluation" or as "plan–do–check".
Walter A. Shewhart
Walter Andrew Shewhart (pronounced like "shoe-heart";
March 18, 1891 – March 11, 1967) was an American physicist, engineer and statistician, sometimes known as the ''father of Statistical process control, statistical quality control'' and also ...
described manufacture under "control"—under statistical control—as a three-step process of specification, production, and inspection.
[ Reprint. Originally published: Washington, DC: Graduate School of the Department of Agriculture, 1939.] He also specifically related this to the scientific method of hypothesis, experiment, and evaluation. Shewhart says that the statistician "must help to change the demand
or goods
Or or OR may refer to:
Arts and entertainment Film and television
* "O.R.", a 1974 episode of List of M*A*S*H episodes (Season 3), M*A*S*H
* Or (My Treasure), a 2004 movie from Israel (''Or'' means "light" in Hebrew)
Music
* Or (album), ''Or ...
by showing
..how to close up the tolerance range and to improve the quality of goods."
Clearly, Shewhart intended the analyst to take action based on the conclusions of the evaluation. According to Deming, during his lectures in Japan in the early 1920s, the Japanese participants shortened the steps to the now traditional ''plan, do, check, act''.
Deming preferred ''plan, do, study, act'' because "study" has connotations in English closer to Shewhart's intent than "check".
![PDCA-Multi-Loop](https://upload.wikimedia.org/wikipedia/commons/4/42/PDCA-Multi-Loop.png)
A fundamental principle of the scientific method and PDCA is iteration—once a hypothesis is confirmed (or negated), executing the cycle again will extend the knowledge further. Repeating the PDCA cycle can bring its users closer to the goal, usually a perfect operation and output.
PDCA (and other forms of scientific problem solving) is also known as a system for developing critical thinking. At Toyota this is also known as "Building people before building cars".
Toyota and other
lean manufacturing
Lean manufacturing is a production method aimed primarily at reducing times within the production system as well as response times from suppliers and to customers. It is closely related to another concept called just-in-time manufacturing ( ...
companies propose that an engaged, problem-solving workforce using PDCA in a culture of critical thinking is better able to innovate and stay ahead of the competition through rigorous problem solving and the subsequent innovations.
Deming continually emphasized iterating towards an improved system, hence PDCA should be repeatedly implemented in spirals of increasing knowledge of the system that converge on the ultimate goal, each cycle closer than the previous. One can envision an open coil spring, with each loop being one cycle of the scientific method, and each complete cycle indicating an increase in our knowledge of the system under study. This approach is based on the belief that our knowledge and skills are limited, but improving. Especially at the start of a project, key information may not be known; the PDCA—scientific method—provides feedback to justify guesses (hypotheses) and increase knowledge. Rather than enter "
analysis paralysis
Analysis paralysis (or paralysis by analysis) describes an individual or group process where overanalyzing or overthinking a situation can cause forward motion or decision-making to become "paralyzed", meaning that no solution or course of acti ...
" to get it perfect the first time, it is better to be approximately right than exactly wrong. With improved knowledge, one may choose to refine or alter the goal (ideal state). The aim of the PDCA cycle is to bring its users closer to whatever goal they choose.
When PDCA is used for complex projects or products with a certain controversy, checking with external stakeholders should happen before the Do stage, since changes to projects and products that are already in detailed design can be costly; this is also seen as Plan-Check-Do-Act.
The rate of change, that is, the rate of improvement, is a key competitive factor in today's world. PDCA allows for major "jumps" in performance ("breakthroughs" often desired in a Western approach), as well as
kaizen
is concept referring to business activities that continuously improve all functions and involve all employees from the CEO to the assembly line workers. ''Kaizen'' also applies to processes, such as purchasing and logistics, that cross organ ...
(frequent small improvements). In the United States a PDCA approach is usually associated with a sizable project involving numerous people's time, and thus managers want to see large "breakthrough" improvements to justify the effort expended. However, the scientific method and PDCA apply to all sorts of projects and improvement activities.
See also
*
COBIT
COBIT (Control Objectives for Information and Related Technologies) is a framework created by ISACA for information technology (IT) management and IT governance.
The framework is business focused and defines a set of generic processes for the ma ...
*
Decision cycle
A decision cycle is a sequence of steps used by an entity on a repeated basis to reach and implement decisions and to learn from the results. The "decision cycle" phrase has a history of use to broadly categorize various methods of making decision ...
*
DMAIC
DMAIC (an acronym for Define, Measure, Analyze, Improve and Control) (pronounced də-MAY-ick) refers to a data-driven improvement cycle used for improving, optimizing and stabilizing business processes and designs. The DMAIC improvement cycle is t ...
*
Intelligence cycle
The Intelligence cycle describes how intelligence is ideally processed in civilian and military intelligence agencies, and law enforcement organizations. It is a closed path consisting of repeating nodes, which (if followed) will result in finish ...
*
Kolb's experiential learning
David A. Kolb published his experiential Learning theory (education), learning theory (ELT) in 1984, inspired by the work of the gestalt psychologist Kurt Lewin. The approach works on two levels: a four-stage learning cycle and four distinct learni ...
*
Lean manufacturing
Lean manufacturing is a production method aimed primarily at reducing times within the production system as well as response times from suppliers and to customers. It is closely related to another concept called just-in-time manufacturing ( ...
*
Learning cycle
A learning cycle is a concept of how people learn from experience. A learning cycle will have a number of stages or phases, the last of which can be followed by the first.
John Dewey
In 1933, John Dewey described five phases or aspects of reflecti ...
*
Lesson study
Lesson study (or ''jugyō kenkyū'') is a teaching improvement process that has origins in Japanese elementary education, where it is a widespread professional development practice. Working in a small group, teachers collaborate with one another, m ...
*
OODA loop
The OODA loop is the cycle ''observe–orient–decide–act'', developed by military strategist and United States Air Force Colonel John Boyd. Boyd applied the concept to the combat operations process, often at the operational level during mi ...
*
Performance management
Performance management (PM) is the process of ensuring that a set of activities and outputs meets an organization's goals in an effective and efficient manner. Performance management can focus on the performance of a whole organization, a d ...
*
Quality storyboard
A quality storyboard is a method for illustrating the quality control process (QC story). Some enterprises have developed a storyboard format for telling the QC story, for example, at Yokogawa-Hewlett-Packard in Japan, the story is told using a fl ...
*
Robert S. Kaplan (closed loop management system)
*
Six Sigma
*
Software development process
In software engineering, a software development process is a process of dividing software development work into smaller, parallel, or sequential steps or sub-processes to improve design, product management. It is also known as a software devel ...
*
Theory of constraints
*
Total security management
References
Further reading
* Reprint. Originally published: ''Quality Management Journal'' 2(1) (1994): 9–24.
*
* 50th anniversary commemorative reissue. Originally published: New York: Van Nostrand, 1931.
{{Authority control
American inventions