Fish Bone

Fish Bone Diagram aso called: Cause-and-Effect Diagram or Ishikawa Diagram

Description:

The Cause and Effect diagram identifies many possible causes for an effect or a problem. Your team can used this to structure a brainstorming session because it immediately sorts ideas into key categories.

Download Fishbone.zip for

1. A 12 page manual on using the Fishbone Diagram.
2. A blank Fishbone form to help you draw the diagram.
3. A MS Excel template for making Fishbones.

When to Use

When your figuring out the possible factors for a problem.

When your teams thinking hits a roadblock.

Procedure:

1- Agree on the problem (effect). Write it at the center right (Fish Head) of the flipchart or whiteboard. Draw a box around it and draw a horizontal arrow running to it.

2- Brainstorm the possible major categories of causes of the problem (5M and 1E).

 Methods

 Machines (equipment)

 Manpower (People)

 Materials

Measurement

Environment 

3- Write the categories of causes as branches from the main arrow.

4- Brainstorm all the possible factors for each of the major categories. Ask: Why does this happen? As each element is given, write it as a branch from the appropriate category (5M ). Causes can be written in several places if they relate to several categories.

5- Again ask why does this happen? about each branch from step 4. Write sub-causes branching off the causes. Continue to ask Why? and generate deeper levels of causes. Layers of branches indicate relationships.

6 After completion, have the team review the diagram. Identify elements that need to be investigated. Circle those items and assign investigation action items to the team.