Chang

The Cause and Effect (a.k.a. Fishbone) Diagram

The Fishbone diagram is also known as the Ishikawa diagram. It was invented by a Japanese quality control statistician, Dr. Kaoru Ishikawa. It is used to deepen a team's understanding of a problem or issue, usually at the corresponding stage of the remodeling process. The process is called Fishbone Analysis because of the way in which the information gathered is arranged visually – like the skeleton of a fish.

When should a fishbone diagram be used?

* Need to study a problem/issue to determine the root cause?

* Want to study all the possible reasons why a process is beginning to have difficulties, problems, or breakdowns?

* Need to identify areas for data collection?

* Want to study why a process is not performing properly or producing the desired results

Because of the function of the fishbone diagram, it may be referred to as a cause-and-effect diagram.

How to draw a fish bone diagram

* Write down the problem on one side.

* Draw a straight line (like the backbone of a fish).

* Draw stems at angles to the backbone line.

* At the end of each of these stems, list the categories.

* For every category, think of several primary causes for the problem.

* For every primary cause, think of supporting reasons (secondary causes).

The major categories typically utilized are:

Manufacturing / Industry:

The 4 M’s: Methods, Machines, Materials, Manpower

The 6 M’s: Methods, Machines, Materials, Manpower, Measurement, Mother Nature

The 9 M’s: Methods, Machines, Materials, Manpower, Measurement, Mother Nature, Maintenance,

Management, Marketing

Service / Office:

The 4 P’s: Place, Procedure, People, Policies

The 8 P’s: Place, Procedure, People, Policies, Price, Promotion, Process, Product

The 4 S’s: Surroundings, Suppliers, Systems, Skills

Any of these categories can be used individually or can be combined in any fashion.

The team should be encouraged to analyze and...