A Pareto chart is a type of chart that contains both bars and a line graph used to assess the most frequently occurring defects by category. It arranges issues in descending order of frequency so the cumulative line shows how much of the total frequency is covered by each category. This allows identification of the most important issues to address to maximize impact on reducing the total frequency. Pareto charts are one of the seven basic tools of quality control and can be created in spreadsheet programs or statistical software.