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.