The cause and effect diagram, also known as a fishbone diagram or Ishikawa diagram, was invented in 1943 by Kaoru Ishikawa to help identify potential causes for a problem. It maps out causes in categories related to a problem or effect. The major purpose is to generate a comprehensive list of possible causes through brainstorming to help understand and solve problems. To create one, the effect is written and main categories of causes are connected. Then detailed potential causes are added as branches in each category. Variations include diagrams for production processes or listing causes before structuring them in the diagram.

1. Cause and Effect Diagram
Reporter:
Almanon, Chelsea E.
Blen, Rose Angelique M.

2. Cause and Effect Diagram
 The Cause & Effect
(CE) diagram, also
sometimes called the
fishbone diagram or
Ishikawa diagram

3. Inventor
 The CE Diagram was invented by
Professor Kaoru Ishikawa of Tokyo
University, a highly regarded Japanese
expert in quality management.
 He first used it in 1943 to help explain to
a group of engineers at Kawasaki Steel
Works how a complex set of factors
could be related to help understand a
problem.

4. Inventor
 Dr. Kaoru Ishikawa, a Japanese quality
control expert, is credited with inventing
the fishbone diagram to help employees
avoid solutions that merely address the
symptoms of a much larger problem.
 CE Diagrams are also often called
Ishikawa Diagrams, after their inventor,
or Fishbone Diagrams because the
diagram itself can look like the skeleton
of a fish.

5. Purpose
 The major purpose of the CE Diagram
is to act as a first step in problem
solving by generating a comprehensive
list of possible causes. It can lead to
immediate identification of major
causes and point to the potential
remedial actions or, failing this, it may
indicate the best potential areas for
further exploration and analysis. At a
minimum, preparing a CE Diagram will
lead to greater understanding of the
problem.

6. Purpose
A fishbone diagram is
useful in brainstorming
sessions to focus
conversation.

7. How to draw CE Diagram
Step 1
 Write down the effect to be investigated and draw
the 'backbone' arrow to it. In the example shown
below the effect is 'Incorrect deliveries'.

8. Step 2
 Identify all the broad areas of enquiry in which the
causes of the effect being investigated may lie.
For incorrect deliveries the diagram may then
become:

9. Step 3
 This step requires the greatest amount of work and
imagination because it requires you (or you and your
team) to write in all the detailed possible causes in
each of the broad areas of enquiry. Each cause
identified should be fully explored for further more
specific causes which, in turn, contribute to them.

10. Different types of CE Diagram
1. Production classification type
 This type differs from the basic type above in that
each discrete stage in the production process
leading up to the effect being examined is shown
along the main arrow or 'backbone' of the
diagram. Possible causes are then shown as
branches off these as shown in the illustration
overleaf.

11. Different types of CE Diagram
2. Cause enumeration type
 This is not so much a different type of
diagram but a different method of
constructing a diagram. Instead of
building up a chart gradually (starting
with the 'backbone', deciding broad
areas, then adding more and more
branches), you postpone drawing the
chart and simply list all the possible
causes first. Then draw the chart in
order to relate the causes to each other.

12. Different types of CE Diagram
2. Cause enumeration type
 This method has the advantage that
the list of possible causes will be
more comprehensive because the
process has a more free-form
nature.
 The disadvantage is that it is more
difficult to draw the diagram from
this list rather than from scratch.