Don’t like the data? Throw it out!

One of the first tasks our Black Belt students are asked to do when completing a project is collect data over time and create control charts for the primary output metric.  The purpose of these control charts is to establish baseline performance, and to determine if the process is stable. One of my students is […] read more

Rational Subgrouping of Data for Control Charts

Control charts are a tool to evaluate the performance of a process over time.   Think of the process as a river that is flowing past the point where we will collect data.  We must decide what to measure, how to measure, where to measure and how often to collect data from the process.   The story […] read more

On March 6th, 2018, posted in: Articles, Six Sigma by Tags: ,

Problems and Issues with Control Charts

Statistical process control charts, aka Shewhart control charts, are introduced in our Green Belt course.  At the Black Belt level, students are tasked to develop control charts for the primary Y variable that is to be the focus of improvement during the Define phase of their Black Belt project. Before we can rely on the […] read more

On August 11th, 2017, posted in: Articles, Six Sigma by Tags:

Control Chart Problems and Issues

I have observed a number of problems and issues with the way that Six Sigma students gather data for, create and interpret control charts.  The purpose of this article is to help you avoid these common problems and issues, and to help you understand how to use control charts as part of a Six Sigma […] read more

On September 16th, 2016, posted in: Articles, Six Sigma by Tags: