There are seven basic quality improvement tools that are used by Quality Circle teams, and are fundamental to the Total Quality Management, Total Quality Control, Lean, and Six Sigma initiatives.

• Cause-and-effect diagrams (sometimes called Ishikawa diagrams, or C&E diagrams, or “fishbone” diagrams)
• Pareto charts
• Process mapping and data gathering tools:
  • check sheets
• Graphical tools:
  • histograms
  • frequency diagrams
  • spot charts
  • pie charts
• Run charts and control charts
• Scatter plots and correlation analysis
• Flowcharts