The Seven Basic Tools of Quality

Source :
http://en.wikipedia.org/wiki/Ishikawa_diagram
http://en.wikipedia.org/wiki/Check_sheet
http://en.wikipedia.org/wiki/Control_chart
http://en.wikipedia.org/wiki/Histogram
http://en.wikipedia.org/wiki/Pareto_chart
http://en.wikipedia.org/wiki/Scatter_diagram
http://en.wikipedia.org/wiki/Stratified_sampling