Why does the Cause Map read left to right?
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It should be noted that the popular fishbone cause-and-effect diagram starts with the problem on the right and builds the causes to the left. It was created by Kaoru Ishikawa (1915-1989) in Japan. The fishbone diagram builds from right to left because the Japanese language reads from right to left. The Cause Mapping method actually uses Ishikawa’s convention by asking Why questions in the direction we read. The fishbone is widely recognized as one of the standard quality tools. Ishikawa was a pioneer with his approach. The fishbone cause-and-effect diagram is part of every Six Sigma program. A Cause Map builds on the original lessons with the fishbone with some subtle but important distinctions.
How does the Cause Map differ from the fishbone approach?
A fishbone starts with just one, single problem, which doesn’t reflect the nature of real-world issues. It reads right to left because the Japanese language reads that direction. It mixes causes and possible causes without specifying evidence. And, it breaks apart the fundamental cause-and-effect relationships within an issue by grouping the causes into general categories.
5-Whys on a Cause Map
The 5-Why approach is an excellent example of basic cause-and-effect analysis. Just as a journey of a thousand miles begins with the first step, every investigation, regardless of size, begins with one Why question. The Why questions then continue, passing through five, until enough Why questions have been asked (and answered) to sufficiently explain the incident. The 5-Why approach, created by Sakichi Toyoda (1867 – 1930), the founder of Toyota, is a simple way to begin any investigation. A Cause Map can start with just one Why question and then expand to accommodate as many Why questions as necessary. Some refer to the Cause Mapping method as “5-Whys on Steroids.”
Some causes are linked with “AND” in between
ANDs show where more than one cause is required. When an effect has more than one cause, both causes are placed on the Cause Map. Each cause is connected to the effect with AND placed in between. These causes are independent of each other, but they are both required to produce that effect. An AND is needed when people provide different, yet valid, explanations of a cause. People think of cause-and-effect as a simple one-to-one relationship: an effect has a cause. In reality, every effect has causes.