The seven basic tools of quality are a standard set of graphical methods for improving quality. They can help with understanding variation and determining the root cause of errors in processes. The seven basic tools are most commonly used within lean manufacturing. All of the tools are graphical methods that do not require much knowledge of statistics. One or more of them can solve most problems within quality improvement.

The set of seven tools became established in Japanese manufacturing during the post-WWII period, when W. Edwards Deming was promoting statistical quality control methods in Japan. The full set of statistical methods Deming taught included more advanced methods, such as design of experiments and hypothesis testing. These were too challenging for many production workers. Manufacturers, therefore, started trying to use simpler graphical methods whenever possible.

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