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

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

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 […]

## How to Calculate Gage Repeatability Using the Average Range

How to Calculate Gage Repeatability Using the Average Range. I’m often asked to help Quality Engineers better understand how to perform Gage R&R calculations. So I decided to write several posts about the topic. Over the next few weeks I plan to roll out a number of posts I trust will enlighten everyone. In this […]

## Reducing Gage RR through multiple readings

Reducing Gage RR can be problematic. Especially when the Gage employed and the process used to a collect the data is the best under the current circumstances. During the Measure phase of Six Sigma a Black Belt will perform a GRR study. This type of Measurement Systems Analysis (MSA) quantifies the error in repeatability and […]