Today we shine the spotlight on the Father of Japanese Quality – Professor Kaoru Ishikawa (1915 – 1989). Instrumental in developing quality initiatives, most notably the quality circle. Karou Ishikawa is probably, best known for inventing the Fishbone diagram (aka 4M/5M or cause and effect diagram), which is used widely today in the analysis of industrial processes.


Kaoru was the eldest of eight sons, born in 1915. He received an engineering degree in applied chemistry at the University of Tokyo and worked at Nissan until 1947. Following, he spent most of his working life as an academic at Tokyo University, until in 1978 he took up the presidency of the Musashi Institute of Technology.


Kaoru Ishikawa is best known for:

  • Seven Tools of Quality – a toolkit to analyse problems and develop improvements.
  • Ishikawa Diagram – cause and effect diagram.
  • Quality Circles – an essential part of Total Quality Management (TQM).
  • Company-wide Quality – quality must be company-wide.


“Quality does not only mean the quality of the product, but also of after sales service, quality of management, the company itself and human life.”
Kaoru Ishikawa.



Ishikawa’s Seven Tools of Quality

Originally published in Japan in 1968, was Ishikawa’s “Guide to Quality Control”.  He believed

90% of the problems in a factory could be solved with just seven simple tools. These tools should be known throughout an organisation and be used to analyse problems and develop improvements. When used together, they form a powerful toolkit. The tools are:

  1. Pareto analysis (which are the big problems?)
  2. Cause and effect (diagrams what causes the problems?)
  3. Stratification (how is the data made up?)
  4. Check sheets (how often it occurs, or is done?)
  5. Histograms (what do overall variations look like?)
  6. Scatter charts (what are the relationships between factors?)
  7. Process control charts (which variations to control, and how?)

These tools can now be found in almost every quality improvement training course.  They are the basic techniques for quality improvement schemes; from baseline setting and benchmarking, through to Six Sigma to value analysis amongst others.


The Ishikawa diagram

One of the most widely known of the seven basic tools of quality is the Ishikawa (or fishbone or cause and effect) diagram.

This tool is used by groups to organise brainstorming and help identify the root cause of problems or issues they have with their product, service or process.

Like other tools, it assists groups in quality improvements. The diagram systematically represents and analyses the real causes behind a problem or effect. It organises the major and minor contributing causes leading to one effect (or problem), defines the problem, and identifies possible and probable causes by narrowing down the possible ones. It also helps groups to be systematic in the generation of ideas and to check that it has stated the direction of causation correctly. The diagrammatic format also helps when presenting results to others.


Quality Circles

It was the introduction of quality circles which was perhaps Kaoru’s greatest achievement.

He believed the involvement of people was vital in achieving quality. He believed everybody had a role to play – hence the introduction of quality circles and making the people involved with the work identify the improvements.

A Quality Circle is a small group of employees who work in the same area or perform the same job. This group meets regularly to identify and collectively resolve the problems in the work area by using the Seven Tools of Quality.


Company-Wide Quality

He believed every function in an organisation contributes to quality. He highlighted the concept of internal customers and Company-wide Quality. This requires the involvement of all, from the top management to the front-line workers, embedding responsibility for quality throughout the whole organisation.

From an organisational point of view, he empowered people and gave them the tools to drive quality through the organisation — his tools de-mystified problem solving. By empowering the the workforce and making quality the responsibility of everyone, he developed a happy and productive workforce who took pride in their work


Find out more about Kaoru Ishikawa

The below courses consider Ishikawa’s theories in more depth:


Further research

If you’re interested in finding out more about Kaoru Ishikawa click on the links below… 

Kaoru Ishikawa – Developing a specifically Japanese quality strategy (ASQ)

Kaoru Ishikawa – the man who invented the fishbone diagram


You can watch the following on YouTube: 

What is a Fishbone Diagram (Ishikawa Diagram)? 

Kaoru Ishikawa – covering his Quality Circle concept and Cause and Effect Diagram  

Who is Kaoru Ishikawa ? – A Quality Guru 

TQM Philosophy of Kaoru Ishikawa