Seven Basic Quality Tools
“The Old Seven.”
“The First Seven.”
“The Basic Seven.”
Quality pros have many names for these seven basic tools of quality, first emphasized by
Kaoru Ishikawa, a professor of engineering at Tokyo University and the father of “quality circles.”
Start your quality journey by mastering these tools, and you'll have a name for them too:
- Cause-and-effect diagram (also called Ishikawa or fishbone chart):
Identifies many possible causes for an effect or problem and sorts ideas into useful categories.
- Check sheet: A structured, prepared form for collecting and analyzing
data; a generic tool that can be adapted for a wide variety of purposes.
Control charts: Graphs used to study how a process changes over time.
- Histogram: The most commonly used graph for showing frequency
distributions, or how often each different value in a set of data occurs.
- Pareto chart: Shows on a bar graph which factors are more
- Scatter diagram: Graphs pairs of numerical data, one variable on each
axis, to look for a relationship.
Stratification: A technique that separates data gathered from a variety of
sources so that patterns can be seen (some lists replace “stratification” with “flowchart” or “run
Excerpted from Nancy R. Tague’s The Quality Toolbox, Second Edition, ASQ
Quality Press, 2004, page 15.