What is the main purpose of a 'Pareto chart'?

A Pareto chart is a specialized bar graph that is used to display the relative importance of various problems or causes in a dataset. The primary purpose of utilizing a Pareto chart stems from the Pareto Principle, which advocates that a small number of causes are responsible for a large portion of effects—in many cases, roughly 80% of problems can be traced back to about 20% of the causes.

By using a Pareto chart, organizations can effectively prioritize issues based on their impact, which allows them to focus efforts on solving the most significant problems first. This strategic prioritization is particularly beneficial in quality improvement initiatives, as it directs resources toward the areas that will yield the greatest overall improvement.

The other options, while relevant to various aspects of data analysis and project management, do not capture the core function of a Pareto chart. The chart does not primarily aim to show just the frequency of defects or visualize process time; rather, it focuses on categorizing problems to assess their effects on overall performance. Additionally, it is not designed to create timelines of project milestones; that task typically falls to Gantt charts or similar project management tools.