Monday, April 11, 2011

What is a Fishbone diagram?


Fishbone diagram is a tool of analysis that provides a systematic way of finding the various causes that lead to a particular effect. It is very useful when we want to carry out brain-storming within a team.

The design of the diagram looks like the skeleton of a fish, hence  it is referred to as the fishbone diagram.
Dr. Kaoru Ishikawa, a Japanese quality control statistician, invented the fishbone diagram also referred to as the Ishikawa diagram.

It is also referred to as a cause-and-effect diagram.

Fishbone diagram helps in categorizing  potential causes of a problem in a systematic way which can ultimately help us in identifying the root causes.

When do we use it:

·       The team needs to study a problem to determine the root cause.

·       Want to study all the possible reasons why a process is having difficulties, problems, or breakdowns.

·       Need to identify areas for data collection.

·       To study why a process is not performing properly or not producing the expected results.

Creating a Fishbone Diagram:

1.    Draw a fishbone skeleton.

2.    List the problem (effect) to be studied in the head of the fish.

3.    Label each bone of the fish. The major categories typically used are:
 
§  The 6 M’s: Method, Machine, Material, Manpower, Measurement,
 Management
§  The 4 P’s: Place, Procedure, People, Policies
§  The 4 S’s: Surroundings, Suppliers, Systems, Skills.

4.    Repeat this procedure with each factor under the category to produce sub-factors. Continue asking, "Why is this happening?" and put additional segments under each factor.

5.    Continue until you no longer get useful information as you ask, "Why is that happening?"

6.    Next step is to collect data with respect to frequency of occurrence of each factor and sub-factor. The frequencies of occurrence are plotted on a Pareto Chart.

7.    The vital few causes appearing on the Pareto chart are the important root causes leading to the problem.

8.    Once the root causes have been identified, the team can further brainstorm to find solutions in respect of the root causes.


2 comments:

  1. hi, it would have been wonderful if there were some examples here as well. i found some more templates and examples in creately diagram community.

    ReplyDelete