The Ishikawa diagram (named after the Japanese chemist Kaoru Ishikawa), also known as the cause-effect diagram, describes the graphic representation of causes that can lead to a result (effect).
Originally, the Ishikawa diagram was used in quality management to analyze the causes of problems. In the meantime the Ishikawa diagram can be transferred to various problem areas (e.g. in production or logistics). The aim is to identify all possible causes and to show the dependencies. The Ishikawa diagram can thus help to break down complex facts and problems and contribute to decision-making.
An Ishikawa diagram is particularly useful when a problem has many potential causes and correlations are not directly apparent. The creation of an Ishikawa diagram within a team increases the transparency of the processes for all members and enables a deeper analysis of the various influencing factors. Relationships between cause and effect are represented in the Ishikawa diagram itself by diagonal and horizontal arrows. Due to its resulting, distinctive shape, the Ishikawa diagram is also referred to as fishbone diagram.