“Quality is not an act , it is a habit.”
Total quality management or TQM is an integrative
philosophy of management for continuously improving
the quality of products and processes.
• Karou Ishikawa is best known for the development of quality tools
called cause-and-effect diagrams, also called fishbone or Ishikawa
diagrams. These diagrams are used for quality problem solving.
• He was the first quality guru to emphasize the importance of the
“internal customer,” the next person in the production process. He
was also one of the first to stress the importance of total company
quality control, rather than just focusing on products and services.
• Dr. Ishikawa believed that everyone in the
company needed to be united with a shared
vision and a common goal. He stressed that
quality initiatives should be pursued at every
level of the organization and that all employees
should be involved.
• Dr. Ishikawa was a proponent of implementation
of quality circles, which are small teams of
employees that volunteer to solve quality
The main goal of the Fishbone diagram is to illustrate
in a graphical way the relationship between a given
outcome and all the factors that influence this
outcome. The main objectives of this tool are:
• Determining the root causes of a problem.
• Focusing on a specific issue without resorting to
complaints and irrelevant discussion.
• Identifying areas where there is a lack of data.
Field of Application
The Fishbone diagram could be applied when it is wanted to:
• Focus attention on one specific issue or problem.
• Focus the team on the causes, not the symptoms.
• Organize and display graphically the various theories about
what the root causes of a problem may be.
• Show the relationship of various factors influencing a
• Reveal important relationships among various variables and
• Provide additional insight into process behaviors.
Fishbone Suggested Categories
(The 4 Ps)
(The 6 Ms)
Analysis of Ishikawa Diagram
• A brainstorming session to generate potential causes
can come up with many potential causes of the
effect in question. The team has to then analyze the
potential causes to decide where to focus their
• The first stage is to highlight those that causes that
are likely to be the main contributing factors, an easy
way to do this is rate each cause, depending on how
detailed you want to be this can be as simple as hot,
warm or cold or rating from 1 to 10.
• The next stage is to look at the remaining “hot”
causes and define actions to resolve them; these
actions can then be rated against both their ease of
implementation and the expense of implementation.
The team first implementing those actions that are
both easy and inexpensive!
• The fishbone diagram and the data can be revisited
on a regular basis as time passes to see how actions
taken affect the problem in question. Thus you can
drive continuous process improvement.
• Helps determine root causes
• Encourages group participation
• Uses an orderly, easy-to-read format to
diagram cause and effect relationships
• Indicates possible causes of variation
• Increases knowledge of the process by
helping everyone to learn more about the
factors at work and how they relate .
• Identifies areas for collecting data