How are fishbone diagrams created?

Fishbone diagrams, which are also known as Ishikawa diagrams, were originally created by Kaoru Ishikawa. They are used to show the causes of specific events. While there are quite a few ways that they are used, it is most commonly a tool for product design and quality defect prevention. They get the name from the fact that they have a line down the middle with lines coming off both the top and bottom, which resembles the bone structure of fish.

Completing a Fishbone Diagram

A fishbone diagram is completed when it includes every cause and effect involved in a given project. Since these diagrams are used to show how an activity is completed from start to finish, the fully filled out fishbone diagram will contain the essential information for a specific project. This could be how to make a specific product, how a hazard causes an injury, or any number of other things.

In order to use the information in the diagram it should be looked at from left to right. Each of the ‘bones’ that comes off the center line needs to be completed before the next one can start. Each ‘bone’ will also have a variety of steps that need to be completed. In many cases the steps on each ‘bone’ will also need to be completed in order so that everything is handled properly.

It is possible to have two or more of the ‘bones’ being worked on at the same time. When this is the case they will be coming off the top and bottom, or right next to each other. This is typically done when two or more activities are not at all dependent on each other. These activities, however, would need to be completed before starting those that are further down on diagram.

The important thing to keep in mind with fishbone diagrams is that they are used to provide details about the work being analyzed. They will typically be useful for long periods of time, which is why it is important to take the time and effort needed to get everything properly placed on the diagram.


View all Lean Manufacturing Q&A

Free E-Book

Lean Manufacturing

Minimize waste and maximize efficiency with our step-by-step guide.


Free Samples

Get samples of our most popular products so you can see the quality before you buy.

Other FREE Resources:

Helpful Resources