Kaizen (pronounced ki-zen) is a Japanese word constructed from two ideographs, the first of which represents change and the second goodness or virtue. Kaizen is commonly used to indicate the progressive long-term betterment of something or someone (continuous improvement) as in the phrase Seikatsu o kaizen suru which means to “better one’s life.” The term Kaizen is used in three ways. The first use is consistent with its literal meaning. The second use is as a companywide management program that establishes a culture focused on continuous improvement of all processes and work places through the elimination of waste. The third use is as the label for a group of methods that improve work processes.

A Principle of Conduct—Striving for Perfection

In its first use, Kaizen means the pursuit of perfection in all one does. In this use, the term is applicable across the areas of one’s life and represents a guiding ethic for conducting a life.

A Management Principle That Creates Business Success

In this second use, Kaizen represents the element of continuous improvement that is a fundamental part of the Quality Model for leading a company to commercial success. In a business context, it is expressed in all activities, personal and teamed, that develop and use learning to make processes better at satisfying customer requirements. In this use, Kaizen has its origins in the fifth of W. Edwards Deming’s 14 management points: “Improve constantly and forever the system of production and service” (Deming, 1982, p. 49). It is commonly expressed as “continuous improvement.” Deming represented continuous improvement as the repeated application of the cycle of Plan, Do, Study, Act (PDSA) to all business activities in the pursuit of making them ever better in delivering value to customers. Its use as a business strategy inside the United States is usually incorporated under the adoption of Deming’s Quality model (e.g., as part of Total Quality Management) or as an element within the Lean Enterprise model described by Womack and his associates (Womack, Jones, and Roos, 1991; Womack and Jones, 2003). Outside the United States, the term kaizen, on its own, more frequently refers to a comprehensive companywide management program best represented by the work of Masaaki Imai (1986). This program establishes a culture focused on the continuous improvement of all processes and work places through the elimination of waste. As stated by Imai, this use of kaizen means “everyday improvement by every person, everywhere” (Imai, 2010). The creation of this culture begins at the top with management. Every manager models and teaches the commitment to continuous improvement by applying it to his or her role and to the systems and processes he or she controls. It spreads across the various functions that constitute a business—executive, administrative, and operational. It is owned by every individual who, as with each manager, seeks ways every day to improve the performance of his or her role and who participates actively in the improvement of the work processes the worker implements and the work places he or she operates within. When used in this manner, the term kaizen umbrellas many other concepts and tools such as customer orientation, total quality control, QC circles, suggestion systems, standardization of work, cooperative employee management relationships, total productive maintenance (Imai, 1986, p. 4). While Imai identifies Japanese management culture as the origin of this approach, in fact it mirrors precisely, but incompletely, the teaching of W. Edwards Deming who brought to the leaders of Japanese industry in the early 1950s these very concepts. He also elaborated the rationale for this approach to business success in what he termed his “system of profound knowledge.” For a detailed explanation of Deming’s thinking see Deming Revisited: The Real Quality Model.

Kaizen as Methods for Work Process Improvement

In its third use, Kaizen identifies a group of methods for making work process improvements. The methods that have been placed under the label Kaizen are varied and range from suggestion systems (Teian Kaizen) to planned events conducted in the workplace that systematically uncover waste in a work process and eliminate it (Gemba Kaizen). In this latter use, Kaizen's origins are in World War II. Kaizen, then known as Job Methods training, was a simple and effective process that enabled workers—initially supervisors—to devise ways to greatly improve the yield from work processes. Its development was spurred by the World War II necessity to produce very much more of everything that was needed for the war effort, faster than anyone ever had done in the past. Before going further into Kaizen's origins as a method for making improvements, let's clarify the varieties of methods that now fall under the label Kaizen.

Varieties of Kaizen Methods

The collection of Kaizen methods can be organized into the following categories:

Individual versus teamed,  
Day-to-day versus special event, and  
Process or value stream level versus subprocess level.  

Individual Versus Teamed
While almost all Kaizen approaches use a teamed approach, there is the method described as Teian Kaizen or personal Kaizen (Japan Human Relations Association, 1990). Teian Kaizen refers to individual employees uncovering improvement opportunities in the course of their day-to-day activities and making suggestions. It does not include making the change itself, but simply the suggestion for the change. However, when used at Toyota within its suggestion system, the employee suggesting the change is the one who almost always makes the change (see The suggestion system is not suggestion). We also use the same term and mean a personal Kaizen wherein a worker uses our Kaizen method (documented in the Kaizen Desk Reference Standard) to improve his or her own job. This effort also unfolds on a day-to-day basis. To my knowledge, all other uses of Kaizen are teamed efforts.

Day-to-Day Versus Special Event
Another example of a day-to-day Kaizen approach is Quality Circles. Here, a natural work team (people working together in the same area, operating the same work process) uses its observations about the work process to identify opportunities for improvement. During any day or perhaps at the end of the week, the team meets and selects a problem from an earlier shift to correct. They analyze its sources, generate ideas for how to eliminate it, and make the improvement. This continuous improvement of the work process is made in the context of regular worker meetings.

Special event Kaizens are currently most common. These methods plan ahead and then execute a process improvement over a period of days. When they focus at the subprocess level, they take place at the work site with the purpose of eliminating waste in a component of a value stream. These special events are performed in the gemba—meaning, "where the real work is being done"—e.g., on the shop floor or at the point where are service is being delivered.

For more details about Kaizen methods and Kaizen's origins, see Six Sigma™ and Kaizen Compared: Part 1 (Revised)


Deming, W.E. (1982). Out of crisis. Cambridge, MA: Massachusetts Institute of Technology Center for Advanced Engineering Study.

Huntzinger, J. (2002). The roots of Lean. Training Within Industry: The origin of Kaizen. Association for Manufacturing Excellence, 18, No. 2. pages 9-22. Retrieved November 22, 2011 http://www.leaninstituut.nl/publications/Roots_of_Lean_TWI.pdf

Imai, M. (1986). Kaizen. The key to Japan's competitive success. New York, NY: McGraw-Hill Publishing Company.

_______ (2010). Definition of kaizen. Retrieved 1/1/2013 from http://www.youtube.com/watch?v=jRdTFis4-3Q

Japan Human Relations Association (1990). Kaizen Teian 2: Guiding Continuous Improvement Through Employee Suggestions. Portland, OR: Productivity Press.

Vitalo, R.L. (2013). Deming revisited: The real quality model. Hope, ME: Vital Enteprises.

Womack, J.; Jones, D.; & Roos, D. (1991). The Machine That Changed the World. New York, NY: HarperCollins Publishers.

Womack, J. & Jones, D. (2003). Lean thinking. (Revised and Updated) New York, NY: Free Press.


1Most people identify Kaikaku as radical change and, in this way, distinguish it from kaizen, which refers to incremental change.

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