An Ishikawa diagram is also known as cause and effect or fishbone diagram. The fishbone diagram is one of the 7 Quality tools. This tool is mainly used to find multiple root causes of one single problem. Fishbone/Ishikawa diagram is one of the effective tools of problem-solving. Fishbone diagram is not just limited to solving a problem in the manufacturing industry, this tool can be effectively used in any industry sector. This tool can also be used to find out the root cause of lack of saving or lack of earning. If you want to learn about fishbone/Ishikawa diagram, this blog helps you to gain knowledge about the fishbone diagram and to implement the same to solve the problem.
This blog covers the following key topics about 5M-1E/Fishbone/Ishikawa Diagram
Who invented Ishikawa tool?
Dr. Kaoru Ishikawa a Japanese professor invented the fish-bone diagram.
Application of Ishikawa / Fish bone diagram:
Fish-bone diagram mostly used for problem-solving in the automotive and other manufacturing industries. Unlike 5 Why analysis, the fish-bone diagram is not just limited to finding a root cause in a single stream. The fish-bone diagram helps to find the root cause in multiple streams / multiple areas. The fish-bone diagram is suitable for solving complex problems.
Fishbone diagram/5m-1e tool is helpful in risk management activities.
To read more about please click the link (risk management word)
To know more about 5Why analysis click this link (5 Why Analysis).
How to draft a fishbone / Ishikawa diagram?
- Define the clear problem statement: The first step of using a fish-bone diagram/cause and effect tool is to define the problem with a clear description by considering the following factors,
- What went wrong?
- Where the problem/defect observed?
- When the problem recorded/observed?
- Who reported the problem/defect?
- Severity of problem?
2. Team formation: This is a very important step for the selection of the right team member for problem-solving. It’s better to identify team members who are familiar with the manufacturing/business process. Subject matter experts can add lots of value to the problem-solving process. For example, a process designer who deployed a business/manufacturing process can add input to build a better fish-bone diagram. Effective team management is required for better coordination between cross-functional team members and successful implementation of the fishbone diagram.
3. Brainstorming: It’s better to conduct a brainstorming session on-shop floor or the place where the problem/defect is identified. If it’s not feasible, you can still conduct a brainstorming session in a meeting room with all the required data and resources. Invite all relevant stakeholders for the brainstorming session. A brainstorming always is effective if it’s lead by a leadership/management team member.
Let’s understand what’s the 5M-1E Ishikawa / Fishbone method.
5M stands for man, machine, method, material & measurement. 1E stands for the environment. 5M-1E fish-bone diagram commonly used in the manufacturing industry as the manufacturing process involved 5M & 1E factors.
For each element, primary cause and secondary cause to be defined. In the brainstorming session, each element must be reviewed carefully for potential root causes of the problem/defect. Primary causes and secondary causes must be reviewed for each element.
It’s a best practice to draft a fish-bone diagram on the whiteboard as it’s easy to amend details on the whiteboard. Once the fish-bone diagram is completed, it must be captured in excel or pdf formats so all details will remain intact.
Following template most commonly used to build the 5M-1E fish-bone / Ishikawa diagram.
The following specifications related to 5M-1E can be considered during brainstorming. Refer to the example of the cause and effect diagram.
| Parameters | Specification | Root Cause |
|---|---|---|
| Man | Training Skill License Stakeholders | |
| Machine | Preventive Maintenance Corrective Maintenance Calibration Machine Set up / adjustment CP, CPk Automation Machine programming Machine Vibrations 5S System | |
| Material | Specification Storage of raw material Key characteristics of parts Handling of raw material Distribution of raw material | |
| Method | Standard Operating Procedure Work instructions Inspection / Test method Audit (process or product audit) Process flow diagram / flowchart | |
| Environment | Temperature Pressure Humidity Vibration Impact Corrosion Dust & Dirt ESD Environment | |
| Measurement | Calibration of tools MSA / Gauge R&R Measurement Technique | |
| Management | Resource Planning Leadership Leadership styles Roles & Responsibility Policy, Commitment Management Review Project Planning |
Note: If the measurement parameter not applicable for solving a problem, add the management parameter in the fishbone diagram.
Fishbone / Ishikawa diagram can be customized based on industry requirements. For example, in 5M-1E, ‘machine’ can be replaced with ‘maintenance’.
Please do refer attached 5M-1E/Fishbone template. This template helps you to draft a root cause specific to man, method, material, machine, measurement, and environment. This template is absolutely free to download.
The 5m-1e methodology can also be used for conducting process audits. Feel free to download thermoforming process audit checklist. Please do visit our Thermoforming process blog post by clicking the embedded link (it will open in a new tab)
Types of Fishbone diagram:
Below specified fish-bone diagrams can be used depending on the type of business process or product/services type.
- 5 M & 1 E – Suitable for manufacturing industry
- 4 S – Suitable for problem resolution in the service industry.
- 8 P -Suitable for problem resolution in the product marketing domain
8P Ishikawa / Fishbone diagram:
This diagram is useful in product marketing strategy.
- Price of the ProductÂ
- Product specification
- Promotion (marketing strategy)
- Place (market)
- ProcessÂ
- People (personnel, trained manpower, stakeholders)
- Physical evidence
- Performance
4S Fish-bone diagram:
4S fish-bone/Ishikawa diagram covers the following element.
- Supplier
- System
- Surrounding
- Skill
Fishbone/Ishikawa diagram: Pros
- Fishbone diagram helps to discover the primary root cause and the secondary root cause of the problem/defect.
- This problem-solving tool is simple to use.
- Fishbone diagram is a useful tool in the six sigma project to identify the root cause in the DMAIC-Analyze phase.
Fishbone/Ishikawa diagram: Cons
1. The Ishikawa/fish-bone diagram is not suitable to solve multiple problems in one fish-bone diagram template. It will become complex and the probability of missing the real root cause will be high. It’s a common practice to use CAPA (Corrective Action & Preventive Action) tool to solve a complex problem.
2. Success of problem-solving by the fish-bone diagram is highly based on cross-functional team coordination and leadership support.
Fishbone diagram Example: A missed project deadline.
Conclusion: If you face problems/defects, don’t worry you can solve them by using Ishikawa/fish-bone diagram. Fish-bone diagram is not just limited to the automotive industry, it can also be applied in farming or agricultural industry.
For example, the root cause of low yield in sugarcane farms can be discovered by using a fish-bone diagram.
Stay tuned, very soon we will share one fish-bone diagram example which is used to solve a low-yield problem in the farming sector.
Read also an article about the Why-Why analysis tool.
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