This post will briefly explain and answer “What is a Control Chart?” and also quickly explain “How to Create a Control Chart?” through a video tutorial of a Control Chart.
First off: entire books and PhD dissertations are written about Control Charts – this short post won’t do it justice. So, please learn on your own what I will most likely not cover in this article.
Every process varies. There is an inherent variation, but it varies between predictable limits. There are two types of variation: “common cause” and “special cause”. If you are cutting diamonds, and someone bumps your elbow, the special cause can be expensive. But, in diamond cutting and no elbow was bumped, the process itself will inherently have variation – that is called common cause.
For many processes, it is important to notice special causes of variation as soon as they occur and appropriately respond.
All control charts have three basic components:
- A centerline, usually the mathematical average of all the samples plotted.
- Upper and lower statistical control limits that define the constraints of common cause variations.
- Performance data plotted over time.
Here is an example of a control chart:

Here is a short video tutorial on how to create a Control Chart:
Factory Physics by Wallace Hopp and Mark Spearman
Pete Abilla
www.shmula.com
Book Review
Aug 21, 2010
I highly recommend this book to operations researchers or lean manufacturing or six sigma or econometric and optimization engineers.
![]() |
![]() |
![]() |
||
This post was written by Pete Abilla | ||||










Jeff Bezos and Root Cause Analysis
The Apple iPhone Supply Chain
The Toyota A3 Report
Queueing, Disneyland, and FastPass
Quality and Continuous Improvement;
{ 2 comments… read them below or add one }
I think you may have wanted to type “common cause” for the example of the diamond cutting with no elbow bumping.
Keep up the good articles. I enjoy them very much!
@Frank – yes, thanks for catching that mistake. Corrected.