Which of the following tools is commonly used for identifying root causes in Six Sigma?

The Fishbone diagram, also known as the Ishikawa diagram or cause-and-effect diagram, is a widely used tool in Six Sigma for identifying root causes of problems. It visually organizes potential causes of a problem into categories, helping teams systematically explore all possible contributing factors. By laying out causes in a structured format, the Fishbone diagram allows teams to delve deeper into the underlying issues rather than just addressing symptoms.

This tool involves brainstorming different categories (such as methods, materials, people, and environment) and plotting the potential causes for the identified problem. As a result, the team can visualize the connections between different factors leading to the issue and prioritize which areas to investigate further.

While the other tools mentioned serve important roles in various phases of problem-solving, they are not primarily designed for root cause analysis. The Pareto chart helps identify the most significant factors based on frequency or impact, the Affinity diagram organizes ideas and information for clarity, and the process control chart monitors process variation over time. None of these tools are specifically focused on uncovering root causes in the same detailed and structured manner as the Fishbone diagram.