number driven data analysis tools
- check sheets
make a check for each occurrence of a particular event - histograms
bar-chart showing ranges along x-axis and frequency of occurence along y-axis - line graphs
compares two variables with time usually plotted along x-axis - control charts
plots data points in time and shows control limits as lines above and below target value line; data outside limits shows special cause variation - Pareto diagrams
bar-chart with ranges with greatest impact sorted toward the y-axis