Control Chart Constants, where did the A2 and E2 constants come from? In statistical process control (SPC) charting, we use the A2 and E2 constants to calculate control limits for an Average (X-bar chart) and Individuals charts. But where do the A2 and E2 constants come from? Let’s look at the following example, for an X-bar […]

## Emotional Sigma – The 8 Step Leadership Coaching Process Use the discipline of Six Sigma to improve Emotional Intelligence and lead people to better business outcomes faster

Emotional Sigma | Using Six Sigma to Improve Emotional Intelligence and Leadership Book Publication Announcement! Are you interested in completing projects linked to strategic business goals sooner? If so, then you know the project team dynamic is crucial. Take, for example, Six Sigma. Black Belts (BBs) must engage various members and, usually, these members have other duties […]

## Emotional Sigma Prelaunch The 8 Step Process to Emotionally Intelligent Leadership

Emotional Sigma Prelaunch Emotional Sigma – An 8 step process to leadership development for executives, managers and business professionals. Learn how to manage your Emotional Sigma by leveraging the discipline of Six Sigma. You’ll improve your Emotional Intelligence, and lead your teams to positive business outcomes faster! Buy the book and get FREE access to […]

## Work Simplification Pioneer – Frank Gilbreth A Great Work Simplification and Lean Practitioner

Work Simplification Pioneer – Frank Gilbreth – A Great Lean Practitioner In 1989 my engineering career began when I completed my undergraduate studies in engineering. Some years later, I began my graduate studies in statistics at the Rochester Institute of Technology. To this point, my career was about using statistics to solve problems and improve […]

## To Know the Problem You Must Experience the Problem This is a Quote I use when working with clients and mentoring Quality Engineering or Six Sigma Practitioners

To Know the Problem You Must Experience the Problem! I get a lot of questions about Quality. Most of the time people want to know how to improve it. Sometimes its a straight forward problem to solve and other times it gets complicated. After years of study and working in the field I’ve learned this: […]

## D2 values for the Distribution of the Average Range Continuing Series in Range Statistics

D2 values for the distribution of the average range appear in the following table. The columns and rows represent the subgroup size (n) and number of subgroups (k). For a given subgroup size, say n=2, notice that the value of d2 changes as the number of subgroups, k, increases. As an example, notice that d2=1.150 […]

## D2 Values Used in Gage Repeatability and Reproducibility Studies Continuing series on Gage R&R Studies

D2 values appear in Gage RR equations when using the Average and Range method. The Average and Range method uses constants to estimate Gage Repeatability and Reproducibility (GR&R). There are two “K” constants “K1” and “K2”. Quality Engineers use them to estimate repeatability and reproducibility. Each of these “K” constants use d2 values in their […]

## Estimating Gage Repeatability Using Range Statistics Continuing series of articles on Gage R&R and Range Statistics

Estimating Gage Repeatability using Range Statistics for one operator is not all that difficult. Is the same true when estimating Gage Repeatability using Range Statistics when using two operators? Let’s discuss this question in more detail… In a previous post we looked at estimating Gage Repeatability using Range Statistics. In that post we examined one […]