Which quality control technique illustrates the 80/20 principle?

According to the PMBOK® Guide, specifically within the Control Quality process, the Pareto chart is a specific type of vertical bar chart used to identify the primary sources that are responsible for the majority of issues or defects.

The 80/20 Principle: The Pareto chart is based on Pareto’s Law (the 80/20 rule), which posits that a relatively small number of causes (20%) typically result in the majority (80%) of the problems or defects.

Functionality: In a Pareto chart, categories are ordered by the frequency of occurrence. This helps the project team focus their corrective actions on the " vital few " problems that are having the greatest impact, rather than the " useful many " minor issues.

Visual Representation: It usually displays both bars (representing individual frequencies) and a line graph (representing the cumulative percentage of the total).

Analysis of Other Options:

A. Ishikawa diagram: Also known as a Fishbone or Cause-and-Effect diagram. It is used to identify the root causes of a problem by mapping out various contributing factors, but it does not rank them by frequency or illustrate the 80/20 rule.

B. Control chart: Used to determine whether or not a process is stable or has predictable performance. It uses " Control Limits " to identify " Special Cause " variation.

C. Run chart: A line graph that shows data points plotted in the order in which they occur. It is used to identify trends and shifts in a process over time but does not categorize or rank causes of defects.