The FishBone Diagram
It is a cause-and-effect diagram which forms from the duo of brainstorming and mind-mapping. The fishbone diagram was invented by Professor Kaoru Ishikawa from Tokyo in 1968. The diagram makes one outline all the possible causes of the related problem; it was commonly used as a quality control tool and also for product design back in the day.
Causes branch from the main categories asked at the beginning, the categories are;
Ø Environment – the location in which the process will happen (including time, temperature and culture).
Ø Machine – equipment required to achieve the task.
Ø Materials – the resources used to display the final product (raw materials, pens, paper, etc).
Ø Measurements – Data received from process that is used to analyze its equality.
Ø Methods – how the process will be done, requirements for carrying it out (rules, regulations, law, procedure).
Ø People – the people involved in process.
Ø Equipment, policies, procedures, and people (recommended for administration and service).
Ways to create your own fishbone diagram
1. Identify the problem under consideration.
State CLEARLY the problem you are working with and write it in a box at the “head” of the fish. Draw a horizontal line from the box until the end of the page.
State CLEARLY the problem you are working with and write it in a box at the “head” of the fish. Draw a horizontal line from the box until the end of the page.
2. Work out major factors which are involved.
These factors include the categories which were discussed earlier (people, methods, measurements, etc.). You may write down any other factors that may come to mind, do not limit yourself. Draw a line off the horizontal line for each factor.
These factors include the categories which were discussed earlier (people, methods, measurements, etc.). You may write down any other factors that may come to mind, do not limit yourself. Draw a line off the horizontal line for each factor.
3. Identify possible causes.
For each factor you wrote down, think of possible causes of the factor and write them down on shorter lines, branching from the “bones” of the diagram.
For each factor you wrote down, think of possible causes of the factor and write them down on shorter lines, branching from the “bones” of the diagram.
4. Analyze your diagram.
This is the last step of the process. At this point, you’re supposed to have all the possible causes that came to mind of the problem. If there are more causes of the causes you have already written down then add them on too.
This is the last step of the process. At this point, you’re supposed to have all the possible causes that came to mind of the problem. If there are more causes of the causes you have already written down then add them on too.
The C&E diagram is also known as the fishbone diagram because it was drawn to resemble the skeleton of a fish, with the main causal categories drawn as "bones" attached to the spine of the fish, as shown below.
Causes in a cause & effect diagram are frequently arranged into four major categories. While these categories can be anything, you will often see:
Other uses for the Cause and Effect tool include the organization diagramming, parts hierarchies, project planning, tree diagrams, and the 5 Why's.
Cause & effect diagrams can also be drawn as tree diagrams, resembling a tree turned on its side. From a single outcome or trunk, branches extend that represent major categories of inputs or causes that create that single outcome. These large branches then lead to smaller and smaller branches of causes all the way down to twigs at the ends. The tree structure has an advantage over the fishbone-style diagram. As a fishbone diagram becomes more and more complex, it becomes difficult to find and compare items that are the same distance from the effect because they are dispersed over the diagram. With the tree structure, all items on the same causal level are aligned vertically.
A fishbone diagram is used to identify the causes or composition of some complex system or event.
Fish Bone Diagrams
Date of access: 12/09/17. Last modified: 5 September 2012 at 09:29
Date of access: 12/09/17.
