
PDCA or plan–do–check–act (sometimes called 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. T ...
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 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 methods of production, method of manufacturing goods aimed primarily at reducing times within the Operations management#Production systems, production system as well as response times from suppliers and customers. It is ...
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 ...
.
The PDCA cycle, with Ishikawa's changes, can be traced back to S. Mizuno of the
Tokyo Institute of Technology
The Tokyo Institute of Technology () was a public university in Meguro, Tokyo, Japan. It merged with Tokyo Medical and Dental University to form the Institute of Science Tokyo on 1 October 2024.
The Tokyo Institute of Technology was a De ...
in 1959.
The PDCA cycle is also known as PDSA cycle (where S stands for ''study''). It was an early means of representing the task areas of traditional quality management. The cycle is sometimes referred to as the Shewhart / Deming cycle since it originated with physicist
Walter Shewhart
Walter Andrew Shewhart (pronounced like "shoe-heart";
March 18, 1891 – March 11, 1967) was an American physicist, engineer and statistician. He is sometimes also known as the ''grandfather of statistical quality control'' and also related to t ...
at the
Bell Telephone Laboratories
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...
in the 1920s. W. Edwards Deming modified the Shewhart cycle in the 1940s and subsequently applied it to management practices in Japan in the 1950s.
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, Study of 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 any 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 plan–do–check–act 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 productive physical capital ...
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
Plan–do–check–act is associated with
W. Edwards Deming
William Edwards Deming (October 14, 1900 – December 20, 1993) was an American business theorist, composer, economist, industrial engineer, management consultant, statistician, and writer. Educated initially as an electrical engineer and later ...
, 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 plac ...
; however, he used PDSA (Plan-Do-Study-Act) and referred to it as the "Shewhart cycle". 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 evidence, empirical method for acquiring knowledge that has been referred to while doing science since at least the 17th century. Historically, it was developed through the centuries from the ancient and ...
, as developed from the work of
Francis Bacon
Francis Bacon, 1st Viscount St Alban (; 22 January 1561 – 9 April 1626) was an English philosopher and statesman who served as Attorney General and Lord Chancellor of England under King James I. Bacon argued for the importance of nat ...
(''
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 Instauratio ...
'', 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. He is sometimes also known as the ''grandfather of Statistical process control, statistical quality con ...
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 goodsby 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 1950s, 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".

A fundamental principle of the scientific method and plan–do–check–act 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.
Plan–do–check–act (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 methods of production, method of manufacturing goods aimed primarily at reducing times within the Operations management#Production systems, production system as well as response times from suppliers and customers. It is ...
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 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 a Japanese concept in business studies which asserts that significant positive results may be achieved due the cumulative effect of many, often small (and even trivial), improvements to all aspects of a company's operations. Kaizen is put ...
(frequent small improvements).
[https://www.agilealliance.org/wp-content/uploads/2016/01/PDCA.pdf ] 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.
Application in Different Industries
The PDCA cycle has proven to be useful across a wide range of sectors. In the manufacturing industry, it is used to reduce defects and optimize efficiency on production lines. In the healthcare sector, it helps improve clinical and administrative processes, such as appointment management and patient safety. In education, it facilitates the continuous evaluation of academic programs and teaching methods, while in the service sector, it contributes to enhancing customer service and user satisfaction.
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 ...
, a business-focused framework for IT management and governance
*
Decision cycle
A decision cycle or decision loop 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 o ...
, sequence of steps used on a repeated basis
*
DMAIC
DMAIC or define, measure, analyze, improve and control (pronounced də-MAY-ick) refers to a data-driven improvement cycle used for optimizing and stabilizing business processes and designs. The DMAIC improvement cycle is the core tool used to driv ...
(''define, measure, analyze, improve and control''), an improvement cycle originally from Six Sigma process improvement system
*
BADIR
The BADIR (pronounced /ˈbaːdɪr/) is a structured data science and data analytics process designed to enhance data-driven decision-making within organizations by addressing both analytical output as well as usefulness to management. It was develo ...
*
Intelligence cycle
The intelligence cycle is an idealized model of how intelligence (information gathering), intelligence is processed in civilian and military intelligence agency, intelligence agencies, and law enforcement organizations. It is a closed path (gra ...
, model of military and law enforcement intelligence processing
*
Kolb's experiential learning
David A. Kolb published his experiential learning theory (ELT) in 1984, inspired by the work of the gestalt psychologist Kurt Lewin, as well as John Dewey and Jean Piaget. The approach works on two levels: a four-stage learning cycle and four dis ...
*
Lean manufacturing
Lean manufacturing is a methods of production, method of manufacturing goods aimed primarily at reducing times within the Operations management#Production systems, production system as well as response times from suppliers and customers. It is ...
*
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 (based on work first published in 1910), John Dewey desc ...
*
Lesson study
A lesson or class is a structured period of time where learning is intended to occur. It involves one or more students (also called pupils or learners in some circumstances) being taught by a teacher or instructor. A lesson may be either one ...
, a teaching improvement process
*
Monitoring and evaluation
Monitoring and Evaluation (M&E) is a combined term for the processes set up by organizations such as companies, government agencies, international organisations and NGOs, with the goal of improving their management of outputs, outcomes and impact. ...
*
OODA loop
The OODA loop (observe, orient, decide, act) is a decision-making model developed by United States Air Force Colonel John Boyd. He applied the concept to the combat operations process, often at the operational level during military campaigns ...
(''observe–orient–decide–act loop''), feedback loop used at operational level in combat operations
*
Performance management
Business performance management (BPM) (also known as corporate performance management (CPM) enterprise performance management (EPM),) is a management approach which encompasses a set of processes and analytical tools to ensure that a business o ...
*
Quality storyboard
*
Robert S. Kaplan (closed loop management system)
*
Six Sigma
Six Sigma (6σ) is a set of techniques and tools for process improvement. It was introduced by American engineer Bill Smith while working at Motorola in 1986.
Six Sigma strategies seek to improve manufacturing quality by identifying and removin ...
*
Software development process
In software engineering, a software development process or software development life cycle (SDLC) is a process of planning and managing software development. It typically involves dividing software development work into smaller, parallel, or s ...
*
Theory of constraints
The theory of constraints (TOC) is a management paradigm that views any manageable system as being limited in achieving more of its goals by a very small number of constraints. There is always at least one constraint, and TOC uses a focusing p ...
*
Total security management
References
Further reading
* Reprint. Originally published: ''Quality Management Journal'' 2(1) (1994): 9–24.
*
*
{{Authority control
American inventions
Quality management
Project management techniques
Systems analysis