Quality tools
The 7 basic quality tools
Interactive versions of the seven basic tools of quality — for collecting data, finding the vital few problems, and tracing them to root causes.
How the seven tools fit together
The seven basic quality tools, popularised by Kaoru Ishikawa, cover most everyday problem solving. They work best as a sequence rather than in isolation:
| Step | Tool | Question it answers |
|---|---|---|
| Collect | Check sheet | What is happening, and how often? |
| Map | Flowchart | Where in the process does it happen? |
| Prioritise | Pareto chart | Which few causes account for most of the problem? |
| Explore causes | Fishbone diagram | What could be causing it? |
| Test a cause | Scatter diagram | Does this factor actually move the result? |
| Understand variation | Histogram | What does the spread look like against the spec? |
| Monitor | Control chart | Is the process stable — and did the fix hold? |