Adopted model · Kaoru Ishikawa
Fishbone diagram
The fishbone diagram is a method for analysing causes and effects which organises, in a clear form, the main groups of causes to which a problem in a given matter can be traced back.
The concept in brief
Using the fishbone diagram, also known as the Ishikawa diagram, we can take stock of the causes behind a given problem. Typically we think along five main groups of causes: people, machines, materials, methods, measurement.
The method works well both individually and in groups: it leaves room for brainstorming, while also providing a framework within which it guides thinking.
Beyond the fixed groups of causes, the number or names of the categories can be changed freely; the emphasis is on recording the cause-and-effect principle and on breaking down the main groups.
The method works well if we work with 3–6 main groups of causes and list 7–12 causes within each group.
The advantages of the method are visual presentation, uncovering hidden links between causes, and finding the origin of a given problem – and so remedying it and preventing it from recurring.