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Kaoru Ishikawa: from fishbones to world peace
  1. M Best,
  2. D Neuhauser
  1. Lake Erie College of Osteopathic Medicine—Bradenton, Bradenton, Florida, USA
  1. M Best, Lake Erie College of Osteopathic Medicine—Bradenton, Bradenton, FL 34211, USA; markbest20{at}

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In management, the first concern of the company is the happiness of the people connected with it. If people do not feel happy and cannot be made happy, that company does not deserve to exist. (Kaoru Ishikawa1)

Today, Kaoru Ishikawa is best known for his diagram which looks like the bones of a fish. His diagram is a practical widely used tool for a group to organise its understanding of the causes of variation in the outcome of their work. He was an unassuming man who saw a link between workplace quality and prosperity. High-quality products would sell, and their makers would prosper. If work was thus made a joyful and human experience, such prosperity and joy would lead to world peace.

Some might find this vision grandiose, but Ishikawa was as responsible as anyone for transforming Japanese industry after the Second World War to focus on high-quality products. This lead to a prosperous, peaceful Japan. The Japanese quality revolution woke up the rest of the industrial world.

Ishikawa believed that quality began with the interaction of people. Top-down (goals) and bottom-up (means) involvement by all members of an organisation is required to optimise quality. Pulling out employee potential is a key leadership skill. Enhancing the quality of life of people enhances the quality of outcomes and productivity of their services. Happy people are more productive and have more pride and responsibility for their work. Ishikawa was one of the first people to emphasise the “internal customer.”


Kaoru Ishikawa was born in Tokyo, Japan, the eldest of eight brothers. His father invited Deming to Japan. In 1939, he was granted a doctorate of philosophy in chemical engineering by the University of Tokyo. He worked as a naval technical officer from 1939 to 1941, then at the Nissan Liquid Fuel Company from 1941 to 1947. He became an associate professor of engineering at the University of Tokyo in 1947, and a full professor in 1960. He expanded on the concepts of Deming and Juran, and wove then into the Japanese culture. Ishikawa was a prolific author and wrote 647 articles and 31 books, some of which have been translated into English.12 He brought statistical process control to the masses by explaining statistics to nonstatisticians. He served as President of the Musashi Institute of Technology and President of the Japanese Society for Quality Control. He was involved in Japanese and international standardisation for decades.

After Deming3 and Juran4 visited Japan, Ishikawa started “Company-wide Quality Control” during the period of 1955–60 and introduced the concept of quality circles in 1962. He wrote two books on quality circles (QC Circle Koryo and How to Operate QC Circle Activities). Quality circles are a bottom-up approach to instilling quality into a product or service. This taps into the area of the organisation where the rubber meets the road, in order to enhace organisational learning and improve quality. Ishikawa has been called the “father of quality circles” for his initiative.

Quality circles

Ishikawa implemented Quality Circles in the 1940s in Japan to engage people at the grass-roots level. It involves people in the same work area to voluntarily meet on a regular basis during normal work hours to identify, select, and evaluate work-related problems, then generate alternative solutions and propose a solution for management to implement. The objective is to increase organisational performance in terms of quality and productivity, improve employee satisfaction, morale and motivation, and develop human resources and teamwork. This taps into creativity, catalyzes innovation, develops leadership and enriches the work place.

His company-wide quality control stressed the entire product life cycle from design to after-sale service, top-down bottom-up management, the organisation itself as a system and the entire human life with enjoyment of work.

He received the American Society for Quality (ASQ)’s Eugene L. Grant Award in 1972, the Japanese government’s Blue Ribbon Medal in 1977 and the Second Order of the Sacred Treasure in 1988, and the Walter A. Shewhart Medal in 1982. In 1993, the ASQ established the Ishikawa Medal as a symbol to recognise individual or team leadership in improving the human side of quality, and called him a “distinguished pioneer in the achievement of respect for humanity in the quality disciplines.”

Seven management tools

  • KJ (Affinity) diagram—The team forms a question (why or what?), each team member writes several facts related to the question, then all the facts are put in groups, headers for each group are created, the headers are arranged into groups and relationships between groups are looked for, then a conclusion is written.

  • Tree (Systematic) diagram—This takes a complex process and breaks it down into assignable tasks. Take a problem, divide it into subcomponents, then divide each subcomponent into subcomponents; this forms a hierarchy with increasing levels of detail.

  • Matrix data analysis chart (MDAC)—This is sometimes replaced with a prioritisation matrix. The MDAC helps make sense of a large number of factors by plotting the points on two dimensions common to all the factors. This shows how each factor is related to each other as well as the two major characteristics on the x and y dimensions.

  • Relations diagram—This shows the relationships between various elements of a problem with arrows pointing from causes to one or more effects. Root causes, key causes, effect(s), and bottlenecks are identified.

  • Matrix diagram—This is used to compare two lists. It shows the relationships and the strength of those relationships, between various items in one list compared with the items in the other list. Special types of matix diagrams can compare three lists to each other.

  • Arrow diagram (Activity Network or PERT Chart)—This is used to manage projects that are composed of interrelated processes. It shows the interdependences of the various tasks and which tasks have to be completed prior to starting other tasks.

  • Process decision programme chart (PDPC)—This is used to identify potential problems or risks that could arise in a project. Thus, countermeasures can be planned ahead of time, or a plan B can be prepared and implemented if needed.

See references67 for a further discussion of these seven management tools.

Ishikawa stressed careful data collection and presentation, using Pareto Diagrams, Ishikawa Diagrams and the other five quality-control tools (process control chart, run chart, histogram, scatter diagram and flow chart).


The Ishikawa diagram (see fig 1), also called the fishbone diagram or cause-and-effect diagram, is used to explore inputs (the four Ms: manpower, materials, methods and machines) that could explain the output (variation or outcome). The Ishikawa diagram is used to encourage employee participation and increases the understanding of processes and can be used to identify root causes of problems or defects, identify possible causes of variation and identify key areas for data collection. It is a way to list many possible causes of variation and opportunities for improvement. The diagram is a way to make visible the production teams understanding of process variation. This is to be done in an open egalitarian discussion format, to draw on everyone’s ideas.

Figure 1 Ishikawa or fishbone diagram: basic structure (the four Ms).

Ishikawa insisted that open-group communication was essential to the proper construction of the diagram. This “systems view” is to insure input from people with expertise and understanding at various levels of the organisation, process and task. Once the diagram is acceptable, the next step is to select key inputs for frequency, perhaps using a Pareto diagram to find how frequently they vary.

The “bones of the fish” or diagram can be expanded as demonstrated in fig 2. The importance is not just the diagram but how it is used as a visual way for the group to understand the causes of variation in their process of work.

Figure 2 Expanded Ishikawa diagram.

Ishikawa had six fundamental principles in his teaching of quality concepts (Greg Watson5 “The Legacy of Ishikawa”):

  • All workers should understand the objectives of companywide quality control and why it is important to business.

  • All levels of the organisation should have a clear understanding of the features of the quality system and confidence in those features.

  • Continuous quality improvement should be cycled many times to standardise work.

  • A long-term quality plan should be defined and implemented systematically.

  • Department walls should be torn down and cross-functional management applied.

  • All people should be confident that their acts will bear fruit.

In referring to Ishikawa (fig 3), Watson5 stated “He proposed a pursuit of quality that can be best described as integrated quality.” Quality is achieved through leadership. The leadership has to focus on the customer, involve all the employees, educate the workers and be committed to the quality practice and philosophy. Ishikawa had a customer-mindedness focus as he reminds us that “customers are the only reason for our business.”5 Ishikawa believed all workers should be involved in quality improvement via teams. Ishikawa taught that education develops understanding and builds character. Education helps to understand truth, and workers become informed skeptics as they remember Ishikawa’s advice: “When you see the data, doubt them! When you see the measurement instrument, doubt it! When you see the analysis, doubt it!”5

Ishikawa described additional tools for quality control beyond the seven listed before.6 7 Ishikawa distinguished between technical and management problems, and created seven tools to help with each. The seven technical tools were listed above and include the Ishikawa diagram. The seven management tools are less well known and are used to apply to organisational problems. These seven management tools include the kj diagram (affinity diagram), tree diagram, matrix data analysis (sometimes substituted with a prioritisation matrix), relations diagram, matrix diagram, arrow diagram (activity network or PERT chart) and process decision programme chart. They focus on issues of organisational complexity as opposed to technical complxity. Though very labour-intensive, these tools use creative or intuitive processes that deal with language-based data, instead of numerical data. These tools allow increased understanding to complex ideas, relationships and systems.

Ishikawa stated “I am convinced world peace and prosperity need quality control. This is why quality control will have to be taught and spread around the world.” With our continued help, Ishikawa’s vision of peace and prosperity may come into being. That would be enough legacy for any immodest person, much less a man like Ishikawa.

There is so much to be learned by studying how Ishikawa managed to accomplish so much during a single lifetime. In my observation, he did so by applying his natural gifts in an exemplary way. He was dedicated to serving society rather than serving himself. His manner was modest, and this elicited the cooperation of others. He followed his own teachings by securing facts and subjecting them to rigorous analysis. He was completely sincere, and as a result was trusted completely. (Eulogy for Ishikawa by Joseph Juran5)



  • Competing interests: None declared.

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