Who Found The Fishbone Diagram?

Fishbone diagram, also known as Ishikawa diagram, is an analysis method used for classification of causes and effects of a problem. This method, which frequently used in quality researches, gets its name from its shape that is similiar to a fishbone. Since Its firstly used by Kaoru Ishikawa in 1943, Its also known with its inventors name, Ishikawa diagram.

Fishbone Cause and Effect Diagram

Fishbone diagram is also known as cause and effect or Ishikawa diagram. Due to Fishbone diagram allows an holistic view to problems, Its an indispensable exercize in brainstorming. Its highly useful when fastly categorizing newly suggested ideas.

When to Use The Fishbone Diagram?

  • To look different suggested ideas when working as a team,
  • To identify possible causes of a problem,
  • In brainstorming when thoughts start to become monotonous,
  • When making cause-effect relationship gets harder, Fishbone diagram can be used.

What are the Steps of Fishbone Diagram / How is it done?

Metot and the diagram consist of 5 steps.

  • Identifying the problem
  • Choosing the root causes
  • Evaluating all causes
  • Determining the sub-categories of causes
  • Complete the missing parts

1st Step: Identifying the Problem

A paper or a board gets taken and a straight line is drawned on top of it. In the group, main problem gets identified while brainstorming. Identified problem written at the end of the line, as the head of a fish, and its sides be framed.

2nd Step: Choosing the Root Causes

A brainstorm is made about the root causes and main titles used in the shceme gets identified. Identified causes written as titles on the arrows that drawn in the horizantal line with 45 degree angles. In this step usually titles like you can see in below are choosen.

  • Metots
  • Equipments
  • Human Resource
  • Materials
  • Measurements
  • Surrondings etc.

3rd Step: Evaluating all causes

All the causes of the problem are being thought and a cause-effect link between all of them are made. In fundamental, an answer to the question “Why did this situation happened?” is searching. New suggested ideas written below a corresponding title.

4th Step: Determining the sub-titles of causes

Determined causes is asked “Why did this problem occur?” and sub-titles are being identified. Branching the causes to sub-titles helps us to meditate and make efficient analysis.

5th Step: Complete the Missing Parts

The datas need to be reviewed after its trasfered to diagram. There might be a need for focusing a cause and adding new ideas to it if its sub-titles didnt looked over much. This step allows us to take the Fishbone diagram as a whole and notice some points we missed if there are any.

Examples of Fishbone Diagram

The Fishbone diagram you see below (Example1), created with the purpose of analysing the causes of fuel waste. In order to approach this problem, firstly the main titles of it has to be identified. In this scheme, according to the objective, the main titles of material, machiene, metot and human have been used. These main titles constitute the body of our skeleton and may vary depending on the current problem.

After completing the backbone, the details of causes are looked into while brainstorming about these titles. This step is very important for elaborating the topic and handling the problem with different angles. New sub-titles which acquired in doing a brainstorme, placed like the Example2 in below creates the bones of the fish. While placing the causes that creates the fishbone usually the order of importance is considered to most important to least important. Because sorting acording to order of importance will make it easier for us to formulate our action plan by revealing the priorities of the problem.

After all the data are placed, the factors causing the problem will be considered together with their causes. After this step, only thing we have to do is create solutions by looking the problem as a whole. In the finding the solution part the Fishbone diagram makes analysing the causes with their sub-causes easier for us.

Benefits of the Fishbone Diagram

  • It ensures that no problem is overlooked by organizing the problem solving process.
  • It provides analytical thinking and effective problem solving skills.
  • With the fishbone diagram, a problem is dealt with in various aspects and away from the fixed point of view.
  • Upskills the creative thinking.
  • Improves the ability to analyze and synthesize.
  • Allows to directly focus on the problem and ensures the topic does not deviate while brainstorming.

Which Program the Fishbone Diagram is Drawn On?

The Diagram can be drawn manually on excel along with templates on Canva. Also empty fishbone and cause-effect diagram templates can be found on internet and you can make use of those.

Since the fishbone diagram is a technique that develops multi-thinking and enables us to deal with the problem with all its causes, it has many the benefit that we cannot count. For this reason, especially for industrial engineering, it comes on top of methods that should be learned and used for many engineering fields. Understanding this diagram gives many profits to identifying the correct cuases in the problem solving step.

Useful Vocabulary

Holistic (adj): considering a whole thing or being to be more than a collection of parts

Monotonous (adj): never changing and therefore boring

Evaluate (something) (v): to form an opinion of the amount, value or quality of something after thinking about it carefully

Sub-title (n): Branching title of an existing main title that gives more information

Purpose (n): the intention, aim or function of something; the thing that something is supposed to achieve

Elaborate (v): to explain or describe something in a more detailed way

Order of Importance (n): a level in a system of ordering things by the guality of being important

Upskill (v): to teach somebody new skills; to learn new skills


Deniz MEHTER