Fishbone Diagram
A fishbone diagram, also known as an Ishikawa diagram or cause and effect diagram, is a visual tool that illustrates the causes of an event. The goal is to find the root cause of an issue instead of implementing a surface-level resolution.
What are fishbone diagrams used for?
Resembling a fish skeleton, these diagrams can be used for:
- Finding ways to improve a process and uncover bottlenecks
- Methodology for creating or assessing product designs
- Quality defect prevention
- Accelerating a process that’s taking a long time
- Pinpointing problems that need addressing to gain or avoid a specific outcome
What are the different types of fishbone diagrams?
Depending on your industry, one type of diagram may suit you better than another. They include:
- Simple: The most basic type of diagram features no preset categories of causes, so you can customize this yourself.
- 8P: This type is named after the eight categories of its composition:
- Procedures
- Policies
- Place
- Product
- People
- Processes
- Price
- Promotion
- 4S: This type organizes information into four categories:
- Suppliers
- Systems
- Surroundings
- Skills
- Man machines materials: This variation is most common in the manufacturing industry and features categories known as the 6 Ms, which make up the “bones” of the diagram:
- Man
- Materials
- Machine
- Methods
- Measurements
- Mother nature (environment)
What are the pros and cons of fishbone diagrams?
Some of the advantages of fishbone diagrams include being applicable to various industries, including manufacturing, product development, healthcare, and more. The method helps you to identify cause and effect relationships while facilitating brainstorm discussions, and is easy to construct.
However, some of the disadvantages are directly tied to its pros. There’s limited room for complexity, which means there may be a disproportionate amount of attention on multiple problems. And while it offers plenty of opportunities for brainstorming, it’s also subjective, which may lead to disagreements among those involved. Additionally, while it can be beneficial to see a visual display of all the potential causes of a problem, this can prove tempting to solve everything all at once. This strategy can be time-consuming and unrealistic—and even deter one from tackling the issue if it seems too large.