The fishbone diagram helps list out the reasons that cause a specific effect to take place. This Workspirited article will explain all about it and also provide you with a free fishbone diagram printable template to download.
The fishbone diagram helps explore all the possible causes that give rise to an effect. It can be efficiently used to enumerate the 5-Whys technique to identify the root causes of a problem, and establish a relationship between them for further analysis.
Also called the cause and effect diagram, the fishbone diagram is an important tool that helps determine why a particular effect had taken place. It is used in a variety of fields to assist managers and other personnel brainstorm solutions to arrive at the root cause/s of a problem. To illustrate further, a very simple example, if a school camp has been successful and the reasons for the same are to be discussed and recorded, this concept can be used. In this case, the effect will be ‘a successful school camp’, and the causes will be enumerated at the sides, which might be listed down as ‘disciplined students’, ‘good food’, ‘good workshops’, ‘games’, etc.
This concept is very useful in enlisting the causes of an event so that improvements can be undertaken the next time. It is explained in detail in the paragraphs below.
- The fishbone diagram was brought to light in 1943, by Dr. Kaoru Ishikawa, a Japanese professor at the University of Tokyo, who had expertise in quality management. That is why it is also called an ‘Ishikawa diagram’.
- It was popularized for identifying the root causes of a problem.
- It is very frequently and widely used by management personnel and other top-notch officers from different profiles and industries in order to brainstorm proper solutions.
- The concept can be used to solve the simplest of problems to the more complex ones involving large companies and other institutions.
- It is essential to remember that the causes must be very carefully categorized while drawing the diagram. The categories can be given generic names, like materials, machines, manpower, measurements, methods, etc.
- It is also nicknamed ‘the cause and effect diagram’, because it enlists, in detail, the causes that produced the effect. Also, since the structure resembles the internal bone structure of a fish, it is called so.
- Write down the effect/problem statement first. If you are using a whiteboard/chart, write it down at the center.
- The problem statement should be enclosed in a rectangle. You may also include details of the problem in your notes.
- Draw a line from the center of the box towards the end. This is the second part of the figure from where the causes will branch out.
- This box represents the head of the fish and this long line represents the spine, and from here, the other branches will develop.
- Now, you need to identify the main categories of causes. This could include any category, and varies with the problem statement.
- For example, the main categories for a manufacturing industry will be manpower, machines, environment, etc.
- The main categories for a server problem will be systems, equipment, LAN, etc.
- All these should be written along the other branches that arise from the main line, and these form the main bone structure.
- These branches should be drawn at an angle of approximately 60° to the main line and 120° when viewed from the side of the problem statement.
- The result should resemble skeleton of a fish.
- Now that you know the main causes, analyze deeper and think about the individual causes.
- In the diagram, these should be drawn as horizontal lines stemming from the branches.
- The causes could include titles or names like lack of motivation, less salary, less bonus, etc.
- Sometimes, the effects of a problem are so profound that even the individual causes seem insufficient.
- In such a scenario, you need to delve deeper by listing the sub-causes.
- The sub-causes or secondary causes could include things like fatigue, ailments, impurities, etc.
- Draw lines at the (60-120) degree angle exactly the same way as done in Step 2. In this case, the individual cause lines act as the main line and the sub-causes act as the main categories.
- In this final step you will have a detailed diagram that enumerates all the reasons for the effect in detail.
- Analyze the figure, focus on different ideas, and come up with a decision regarding why the problem occurred, and how it can be solved/avoided in future.
- This is a crucial step, for you have to do some serious thinking regarding the causes and come up with an effective solution.
- Let the problem statement be ‘Poor Mid-term Results’.
- The main categories can be ‘Teachers’, ‘Papers’, ‘Students’, and ‘Syllabus’.
- Under ‘Teachers’, the reasons can be ‘Poor Teaching Methods’ and ‘Poor Language’.
- Poor teaching methods could include ‘rote learning’, ‘using wrong books’, etc.
- Under ‘using wrong books’, you could have ‘books are not recommended’ as the secondary cause.
- Similarly, poor language could include ‘poor English usage’ or ‘Poor Spanish usage’, etc.
- Similarly, the other categories can be scrutinized.
- Under ‘Syllabus’, you could have ‘Wrong Syllabus’, under which you can have ‘Incorrect paper referred’.
- Under ‘Papers’, you can have ‘Incorrect paper provided’.
- This analysis can continue until you are confident enough about having listed all the reasons that caused the poor mid-term results.
- This will provide an opportunity for the teachers to improve their teaching methods, set the correct papers, have proper grading systems, etc. It will also help students to refer to the correct books, study properly, and write what is expected.
- Let the problem statement be ‘Deadline Not Met’.
- The main categories here can be listed as ‘Increased Workforce Absence’, ‘Extra Work’, ‘Inefficiency’, and ‘Other Departments’.
- Under ‘Increased Absence’, your individual causes could be ‘Illness’, ‘Emergency’, ‘Personal’, etc. Within ‘Illness’, your cause would be ‘Admitted to Hospital’, under which, a secondary cause could be ‘Malaria’. Therefore, this is one of the reasons the deadline could not be met.
- Similarly, under ‘Extra Work’, your individual cause could be ‘Testing’ (if at all you are already handling the coding part of the program), under which, you can have ‘Testing only Module 1’, within that, you can have a secondary cause as ‘Using Black-Box Testing’.
- This essentially means that you are taking on an additional job, which is not included in your job profile, and hence, you have not been able to meet the deadline.
- Again, under ‘Inefficiency’, you can have individual causes as ‘Less Productive’, ‘Sloppy Work’, etc.
- Under ‘Less Productive’, you could have the primary cause as ‘Not used efficient online tools’, under which, the secondary cause could include the names of the tools.
- This means that your work has been inefficient and non-productive as per required standards, because you have not used the tools that could have sped up the process, and consequently, it has not helped you meet the necessary deadline.
This kind of root-analysis can go on and on, until you completely comprehend the reasons of the problem, and take the correct decision.
- The above figure is a rough fishbone diagram of a manufacturing problem.
- In manufacturing, the categories are generally divided into the 6Ms―material, machines, manpower, methods, Mother nature (environmental), method, and measurement. These 6 categories form the main skeleton.
- The problem statement could be anything, say, poor production to bad customer reviews.
- The first category is personnel or manpower, which has individual causes as ‘shifts’, ‘training’, and ‘operators’.
- Shifts could mean the erratic timings of the workers’ shifts, training could mean unplanned training modules, while operators could mean the execution staff who have probably not achieved their targets. All this might have contributed to the problem.
- The second category is material, under which, there are 2 individual causes; namely, ‘stainless’ and ‘carbon steel’. This could indicate poor quality of the material, or probably the fact that the materials have been damaged.
- The third category is measurements, which enlists the individual cause to be ‘calibration tolerance’. These could mean significant calculation errors due to which the production might have been hampered.
- The fourth category below is environmental, which indicates the unexpected acts of Mother Nature.
- The individual cause here has been given as ‘ambient humidity’. This indicates that some problem has occurred due to the humid weather, which has affected the production schedule.
- The fifth category is methods, within which, ‘grinding’ and ‘welding’ have been listed.
- This indicates that both procedures have been carried out incorrectly, or probably carried out on the wrong batch of material, due to which there has been considerable loss.
- The sixth and last category is machines.
- Under this, the individual causes are ‘gear wear’ and ‘speed’.
- The former possibly indicates the wear and tear of the gear, while the latter indicates some problem to have occurred regarding the speed of the machine.
- Both causes have contributed to the overall effect.
In the above figure, you can see that no sub-causes have been unearthed, probably because there was no necessity. By analyzing this diagram, the managers and other staff would have probably realized the root causes of the problem and would have come to a decision regarding how to solve the same. Possibly, they could have better training sessions, higher quality material, improved technology, etc. Thus, this concept helps one understand the causes and draw solutions.
- The causes of a problem can be effectively categorized.
- Since it needs to be visually created, it is easy to learn and understand.
- The visual aspect stimulates creativity among the staff.
- It also encourages ‘System Thinking’.
- The entire process requires, to an extent, that all the working staff get involved, and this increases overall knowledge and learning.
- The discussion regarding the causes keeps everybody updated about the current market situation.
- It promotes corrective analysis and relevant actions.
The fishbone diagram is a great tool to develop understanding of the causal factors for a problem. Creating it will help develop new knowledge and cultivate trust amongst employees. It has been used since decades as a great process improvement tool due to its clarity and effectiveness. It also helps focus better on reducing company losses and improving as a team in general.