Module 3 Gage R&R Studies

Lesson M3-07

Text: Section 2

Duration: 20 minutes

Exercises – Analyzing Gage R&R Studies (ANOVA)

A few exercises follow, giving you a chance to practice analyzing and interpreting Gage R&R results.

Downloads

Exercise 1-4.5.MTW

Exercise 1-4.6.MTW

Module 3 Gage R&R Studies

Lesson M3-06

Text: Section 2

Duration: 15 minutes

Analyzing a Gage R&R in Minitab (ANOVA Method)

In this lesson, we illustrate the analysis of Gage R&R data for a standard crossed study using the ANOVA method.   We review the statistical output and focus on the ANOVA table interpretation.  In addition to the standard graphical output, an individual value plot showing all the raw data is presented as a good practice.  We end with a discussion of reasons for poor repeatability and poor reproducibility.

Module 3 Gage R&R Studies

Lesson M3-05

Text: Section 2, pages 20 – 34

Duration: 30 minutes

Analysis – ANOVA Method

In lesson 5, we introduce Analysis of Variance (ANOVA) and explain why the ANOVA method for analyzing Gage R&R studies is superior to the Average and Range Method.  Through an example dataset, we illustrate the calculation of the variance components and then show how those are normalized in the Mean Square column of the ANOVA table.  Then, we explain the purpose of the F statistic and its interpretation.  This is used to determine if a specific variance component is statistically significant (i.e. larger than the error).  We then show how you could calculate the key Gage R&R metrics (e.g. EV, AV, RR) from the ANOVA table output, although we will continue to use Minitab software for the calculations.

Downloads

MSA Gage RR Example 2.MTW

Module 3 Gage R&R Studies

Lesson M3-04

Text: Section 2

Duration: 14 minutes

Exercise – Analyzing a Gage R&R Study

This lesson allows you to practice analyzing and interpreting a Gage R&R study in Minitab (using the Average and Range Method)

Downloads

Exercise 1-4.4.MTW

Module 3 Gage R&R Studies

Lesson M3-03

Text: Section 2

Duration: 28 minutes

Setting up and Analyzing a Gage R&R in Minitab

In this lesson, we demonstrate how to create a Gage R&R worksheet in Minitab.  This is not required but may be helpful to organize the study.  Then we illustrate the analysis of Gage R&R data for a standard crossed study.  We review the statistical output so we’re sure how to find the key statistics we defined earlier.  The graphical output provided is also discussed.  We illustrate how to enter a historical (process) standard deviation so that the %Process RR statistics will be calculated.

Downloads

MSA Gage RR Example 1.MTW

Module 3 Gage R&R Studies

Lesson M3-02

Text: Section 2, pages 5 – 15

Duration: 27 minutes

Analysis – Average and Range Method

We review a basic calculation worksheet for using the average and range method to estimate measurement error components.  Understanding the calculations helps us understand how we isolate repeatability variation and calculate reproducibility.  In this method, specific ranges are calculated and then used to estimate standard deviations.  An example illustrates the calculations of the normal metrics.  We end with a review of the guidelines for acceptance and a discussion of possible causes of poor repeatability and/or poor reproducibility.

Downloads

Gage R&R Worksheet (Excel xls format)

References

Here are the course reference documents.

Download the course Participant Guide pdf to follow along with the presentations and exercises.

Download the Measurement Systems Assessment course reference text for additional reading on the course topics.

Or, you may purchase hard copies of these, if desired. The references are at the Integral Concepts marketplace at Mimeo.com. The link takes you to the All Products screen. Click on the left sidebar menu item “Measurement Systems Assessments” to view the available hardcopy references for this course.

Downloads

These are the downloads all in one place, in order of appearance in the course. You will also find a link for worksheets, example datasets, and exercise datasets on the lesson page where the download is mentioned. All downloads are Minitab .MTW files unless otherwise noted.

Gage R&R Worksheet (Excel .xls format)

MSA Gage RR Example 1.MTW

Exercise 1-4.4.MTW

MSA Gage RR Example 2.MTW

Exercise 1-4.5.MTW

Exercise 1-4.6.MTW

Expanded Gage RR.MTW

SA SPC Example-1.MTW

MSA SPC Example-2.MTW

MSA SPC Example-3.MTW

MSA SPC Example-4.MTW

Exercise 1-4.7.MTW

Exercise 1-4.8.MTW

MSA Attribute Example-1.MTW

MSA Attribute Example-2.MTW

Exercise 1-4.10.MTW

MSA Attribute Agreement Example Template Inspection of Taper.MTW

MSA Attribute Agreement Example Print Integrity.MTW

Exercise 1-4.11.MTW

Exercise 1-4.11.xls (Excel .xls format)

Exercise 1-4.12.MTW

Exercise 1-4.13.MTW

MSA Nesting Example-1.MTW

Exercise 1-4.14.MTW

MSA Grubbs Worksheet.xls(Excel .xls format)

Exercise 1-4.15.xls (Excel .xls format)

Module 3 Gage R&R Studies

Lesson M3-01

Text: Section 2, pages 1 – 4

Duration: 18 minutes

Overview and Planning for a Gage R&R Study

In this first lesson, we discuss planning for a Gage R&R study.  Selecting a sample of parts to be measured is an important aspect of the study and this is discussed in some detail.  We also discuss randomizing and blinding the study as ways to prevent bias in the results.  Finally, we talk about typical sample sizes and who should participate in the study.

Module 3 Gage R&R Studies

Lesson M3-00

Text: Section 2

Duration: 2 minutes

Gage R&R Studies Module Introduction

Module 3 covers the planning, conduct, and analysis of data for Gage Repeatability and Reproducibility Studies. We start with planning guidelines that cover sample sizes, specimen selection, and suggestions for conducting the study.  Next, we introduce one method for estimating the measurement error components called the Average and Range Method which is simple enough be done in Excel.  We demonstrate how to set up and analyze a Gage R&R study in Minitab.  Then we introduce Analysis of Variance (ANOVA) and the use of this method for analyzing Gage R&R studies.  Several of the benefits of ANOVA are discussed including better precision of variance estimates, allowance for expanded studies, ability to estimate interactions, and ability to compute confidence intervals.  The last lesson illustrates the analysis of an expanded Gage R&R study where additional factors may be included into the study.

Module 2 MSA Definitions

Lesson M2-07

Text:

Duration: 8 minutes

MSA Definitions Module Introduction

In lesson 7, you have a chance to test your understanding of some of the key concepts covered in this foundational module.

Module 2 MSA Definitions

Lesson M2-06

Text: Section 1, Pages 25 – 33

Duration: 20 minutes

Measurement Systems Characteristics – Part II

In this lesson, we introduce the concept of linearity with respect to both accuracy and precision.  We use simple scatter plots to illustrate the linearity of systems and do a couple of short exercises to understand the concepts.

*Note: when playback pauses during an exercise, click anywhere on the screen (not the menu) to continue.

Module 2 MSA Definitions

Lesson M2-05

Text: Section 1, Pages 19 – 24

Duration: 25 minutes

Common Gage RR Metrics

Although we will mostly apply these in the next module, in Lesson 5 we define the common metrics uses to judge the results of a Gage R&R study.  These include, % Tolerance RR, % Process RR, % Process RR based on variances, and ndc.  We also discuss the questions that these metrics are intended to answer.  Finally, we provide guidelines for determining the acceptability of the metrics.

Module 2 MSA Definitions

Lesson M2-04

Text: Section 1, Pages 13 – 18

Duration: 23 minutes

Repeatability & Reproducibility

In the next lesson, we break down precision into the components of repeatability and reproducibility.  These are defined conceptually and mathematically through the use of statistics such as the standard deviation and the coverage range of the normal distribution that is used to model measurement error.  We summarize all the components of the total variation and finally discuss how these components may be added together using variances.

Module 2 MSA Definitions

Lesson M2-02

Text:

Duration: 25 minutes

Review of Basic Statistics

In Lesson 2, we provide a review of basic statistics and concepts that will be used throughout the course.  We first define data types (variable and attribute) that will determine how we assess the systems that produce data of each type.  Since we typically use the normal distribution to model measurement error, we review the characteristics of this distribution.  Then we review basic descriptive statistics that describe central tendency (means and medians) and variation (range, standard deviation, and variance).