Surely someday when you were eating a fish you felt uncomfortable with its spine, did not you? So, incredible as it may seem, it's going to be about that spine that I'm going to talk about in this article.

Calm down, it's not an article about food. When I speak about the spine I want to speak in fact about Ishikawa Diagram. This is all due to its shape, which is very reminiscent of a fish's skeleton.

In this article, I'll tell you everything you need to know about this diagram, from its historical context, its functionality, the pros and cons and a brief way to set it up. Enough of wasting time and let's get down to business!


How did the Ishikawa Diagram arise?


The Ishikawa Diagram was proposed by a Japanese quality control engineer in the early 1960s. And the name of that engineer is Kaoru Ishikawa. That is the origin of the name of this diagram.

This diagram has suffered some changes through time. It has been evolving and adapting according to the needs.

As Ishikawa himself said, "quality improvement is a continuous process and can always be improved."


After all, what is and what is the function of this diagram?

Resultado de imagem para ishikawa diagram


The Ishikawa Diagram, also known as Cause and Effect Diagram and also as Fishbone Diagram is one of the 7 tools that make up the quality.

Basically, it is a tool that aims to organize the rationale in identifying root causes of problems. It relates the effect to be analyzed with the most influential causes.

These causes of problems can be classified into 6 different types of major causes that affect the whole process (machine, materials, manpower, mother nature, measure and method).

You noticed all these causes start with "M", did not you? So, because of this, these causes are also known as 6 M's.

But it is important to remember that not all processes use all of these M's for pointing the causes, so it is important to evaluate which ones are important to the process.

Now you will understand a little more about each one of them and their main characteristics.


Understand more about the 6 M's of the Diagram!


1. Machine


Many problems are derived from the failures of machines and equipment. This may be caused by improper maintenance or the lack of maintenance.

Considering this, it is always important to supervise the operation of all equipment, so the operation is close to perfection, avoiding damages.


2. Materials


This problem is related to the use of materials in the process. May be related to out-of-spec material or incorrect volume.

For this reason, it is extremely important to have a good relationship with your supplier, so that he offers correct products, in the right quantity and of course, in the ideal quality.


3. Manpower


It is related to the attitudes of employees in the execution of activities. This problem can be caused by their haste, recklessness, lack of qualification or even lack of competence.

You know humans are susceptible to failure, don’t you? So, in order to avoid errors in certain processes, it is recommended to use the Poka Yoke.

But what is Poka Yoke? It is an error-proof device designed to avoid defects in manufacturing processes.


4. Mother Nature


These are problems related to the internal and external environment of the organization.

When talking about external you can talk about pollution and the weather instability, for example. And in the internal environment, it could be the lack of space, incorrect layout, noise, among others.

It is crucial to have a working environment favorable to everyone, so that they have a greater pleasure in performing their duties. With everything working as planned, you reduce the rotation of the employees, reducing cost and consequently increasing the profit.


5. Measure


This "M" is related to the metrics used to measure, control and monitor processes.

You may be using an incorrect way to measure your process. This is generating rework and harming your process.


6. Method


Refers to the procedures and methods adopted by the organization during activities.

The method can defined through software and planning tools. It represents the way you plan the progress of your activities and how to control what is happening.


What are the advantages of using the Ishikawa Diagram?


There are many advantages to using this quality tool in the business environment. I will now list 6 of them so you can think about it:


1 - The first benefit of using the diagram is the fact that is a visual tool, easy to understand and easy to analyze ;

2 - It influences all employees involved in the process to commit to the results to be achieved;

3 - It helps to find the root cause of the problem;

4 - Can be used as a statistical tool for total quality control;

5 - It prioritizes an analysis in more detail, helping to make more effective decisions;

6 - It has a generic use and flexible structure, being applicable in problems of different natures.


Life is not a bed of roses ...


Despite its great applicability and simplicity in cause deffinition, the tool has not only positive points. We can cite some disadvantages, such as:


  • It does not signal the real gravity of the problem;

  • Often effort is wasted in identifying the cause of effects that have no great relevance.


In addition to these disadvantages it is necessary to take some precautions when developing and implementing the Ishikawa Diagram:


  • It should be used preferably by employees who already have some knowledge about the PDCA cycle;

  • Because it is a relatively simple tool, it is necessary to have a business structure favorable to this implement;

  • Because they cover different areas and a large number of people, it is possible that exists different opinions, being necessary to know how to administer them.


A brief step-by-step on how to do the Ishikawa Diagram:


Step 1: First of all you have to determine what the effect (or problem) is to study.

Step 2: With the determined effect, you have to gather all the information about this problem and this will be the basis for the next step.

Step 3: Bring together a multidisciplinary team from different areas, so that they can help in the creation of the Ishikawa Diagram.

After presenting the information about the diagram it is necessary to promote a brainstorming about the problem that needs to be solved.

Maybe you must be wondering, "What is brainstorming?" Basically, it is an activity designed to explore the creative potentiality of an individual or, as in this case, a group.

Step 4: The main causes must be studied, classified and prioritized, so actions can be elaborated focused on correcting the pririty causes of the problem.

Step 5: We have reached the last step! In it, you need to draw the diagram according to the 6 M's. Be very careful because it will be this design that the whole team will follow.


Extremely important tool!


The Ishikawa Diagram is a valuable tool in discovering the root cause of a problem. It brings a lot of benefits to the whole process.

With a clearer view of the effects, it is possible to take corrective and preventive measures on the problem more effectively, and then eliminate its root cause.

Nowadays, all sectors, whether in industry, marketing, finance and others, use this diagram constantly, showing the importance of it.

And it's important to remember, always focus on the client when proposing the actions, as they are the most responsible for the success of your company.