Six Sigma Green Belt Certification Practice Exam

Which tool is used as a form of quality control to monitor variables and parameters during process baseline estimation?

1. Flow charts

2. Histograms

3. Process maps

4. SPC charts

The correct answer is: SPC charts

SPC charts, or Statistical Process Control charts, are specifically designed for monitoring a process over time to identify any variations or trends that may indicate issues in the process. They help in distinguishing between common cause variation (inherent to the process) and special cause variation (caused by specific, identifiable factors). By using SPC charts during process baseline estimation, quality control personnel can observe the performance of variables and parameters in real-time, enabling timely interventions when the process goes off-target. This proactive approach helps ensure that the process remains stable and operates within the defined quality limits. Flow charts, histograms, and process maps serve different purposes in quality management. Flow charts illustrate a process and its steps, but they do not monitor variation over time. Histograms provide a visual representation of data distribution, which is useful for understanding data characteristics but not for ongoing process monitoring. Process maps detail the flow of processes, similar to flow charts, but focus more on the sequence of activities than on variable control. While all of these tools are valuable in their own right, SPC charts are uniquely suited for the purpose of ongoing process control and monitoring.