A fishbone diagram is built in several stages.
- Define the target problem or situation that needs to be analyzed.
- Choose the categories into which the causes will be grouped. Examples of such categories are people, equipment, materials, methods, environment, management, and activities that can directly affect the final result.
- Brainstorm to identify all possible causes, then write them down and display them visually.
- Link the causes to show how they are related and determine the roots of the problem.
- Work with the resulting data to identify the priority areas that need improvement.
What is the principle behind the diagram? It assumes that a problem can arise from several closely related causes. When drawing a fishbone diagram, keep the following in mind:
- define the target problem precisely and do not drift away from it when identifying possible causes;
- analyze all possible causes thoroughly, even if at first they seem insignificant;
- draw logically sound connections between the causes you find.
Follow a specific sequence when building the diagram.
- Start by drawing the main problem in the center. This can be a malfunction or a difficulty that needs to be resolved.
- Identify the key factors that may be the root source of the problem. They are drawn as lines or branches coming off the main problem, like the bones of a fish.
- Identify the secondary factors that can aggravate the root causes. They are placed on the lines connected to the main factors.
The method is considered analytical because it helps break down complex problems or situations and identify and classify the key factors that affect the result. The final step is to develop a strategy to eliminate the negative factors. The main advantage of the diagram is that it lets you examine a problem in detail from different angles and ultimately find the best solution.
Common mistakes
No process is free of mistakes. Here are the typical errors that can occur when building an Ishikawa diagram.
- Defining the core target problem incorrectly, which leads to errors in identifying causes.
- Too few brainstorming participants, which causes important sources of the problem to be missed.
- Grouping causes into the wrong categories, which creates confusion and makes analysis harder.
- Not explaining the links between root causes clearly enough, which makes it impossible to understand where the problem really comes from.
It is also important to keep the analysis objective and to order the factors consistently; otherwise, the result suffers.
Tools for building an Ishikawa diagram
You will need a few tools to build an Ishikawa diagram.
- Prepare a whiteboard or a large sheet of paper in advance to draw the diagram.
- You will need markers in different colors to highlight different categories and causes.
- You will also need brainstorming participants who will work on identifying root causes and their connections.
You can also use a computer. Various programs can help you draw a fishbone diagram, such as Microsoft Word, XMind, or Microsoft Paint.
Online services are also worth considering: Canva, MindMeister, Lucidchart, and Creately. These tools let you create professional diagrams quickly and easily.
Let's look at why brainstorming helps find the source of a problem.
- Different points of view. Invite specialists with different experience and knowledge so the situation can be viewed from different angles.
- New ideas. People's creative thinking is the first step toward finding unconventional solutions.
- Collective reasoning. Group discussion helps uncover hidden causes and connections.
- Synergy. The joint efforts of participants can lead to the discovery of non-obvious factors that indirectly affect the problem.
- Objectivity. Involving several people helps avoid subjectivity and bias.
Brainstorming participants can include representatives of different company departments and specialists in a particular field. It is important to have both experts and people with hands-on experience and different points of view.
To run a brainstorming session effectively:
- define goals and objectives in advance;
- create an atmosphere of openness and support for participants' ideas;
- use various techniques to stimulate thinking, such as exercises and special games;
- write all ideas on a board or a sheet of paper;
- set deadlines and an action plan for each identified factor;
- encourage discussion and dialogue;
- use analytical tools to assess how strongly each factor affects the problem;
- bring participants' efforts together to find a joint solution.
For best results, use no more than 5-7 main factors when building an Ishikawa diagram. This approach lets you concentrate on the main root causes and avoid unnecessary complexity. The resulting action plan should be specific, measurable, and realistic, and it should assign an owner to each step.
Ishikawa diagram example
Let's look at an example. Suppose the goal of an Ishikawa diagram is to reduce the number of equipment failures. We identify the following categories of causes: technology, processes, the equipment itself, and staff training. Examples of causes include:
- insufficient staff training on new technologies;
- inefficient production processes;
- poor equipment condition;
- uneven distribution of workload.
In education, the method might be used like this. A teacher applies it to analyze in detail why students performed poorly on an exam. An Ishikawa diagram makes it easy to identify the basic causes of failure:
- insufficient preparation;
- unclear instructions for the assignment;
- lack of motivation.
A strategy for improving the learning process can then be developed.
In business, the fishbone diagram is used to study the root causes of failures, problems, and defects in production processes. Managers can use it to identify and eliminate the causes of an unacceptably high defect rate.
Using the diagram has both pros and cons. The pros include:
- a chance to identify the causes of a problem;
- better communication within the team;
- the possibility of a quick and effective solution.
The cons are that the process takes quite a long time and requires careful, meticulous analysis skills. Even so, there is a risk of getting an inaccurate result.
Nevertheless, the Ishikawa diagram remains relevant and effective today. It helps structure and analyze complex problems, identify and eliminate their root causes, and make more informed decisions.
