Posted by: meikah | 12 March 2007 | 4:24 am
A Control Chart is one of the seven basic statistical tools often used in Six Sigma, along with the Pareto Chart, histogram, check sheet, cause-and-effect diagram, flowchart, and scatter diagram.
Also known as the Shewhard chart or process-behavior chart, it can monitor processes and assure that they remain stable.
Six Sigma on its part is data-driven and aims for processes to be stable and continue to improve for as long as the processes are working.
When you use a Control Chart therefore in your Six Sigma project, you can better evaluate your data and monitor your processes.
Business Knowledge Source, Manufacturing Info reports that:
Control Chart Control charts help distinguish process variation due to assignable causes from those due to unassignable causes. Both these types of process variation are charted on a control chart. Assignable causes or special causes are meaningful factors of a process and are not always present or normal. These types of causes can be avoided and should be investigated. Unassignable causes are also known as common causes or chance causes. These are factors that occur by chance. They are not always present, but are normal and expected within a process. They are unavoidable and inherent in a process.
Business Knowledge Source, What is a control chart and how is it used in Six Sigma? with a link from Six Sigma Zone