PQ Systems, Inc. | Quality Blog

We frequently entertain questions about MSA and specifically, gage R&R. Below are two questions we recently received:

Question #1: “What are the requirements for the parts chosen in a study? Do the parts have to have the same specification?”

Answer: The parts selected should be representative of the process variation that is producing them. This implies that selecting 10 consecutive pieces (parts) is not as good as using 10 parts obtained throughout the day or week. Part of what you are trying to do with an R&R study is determine whether your measurement system is capable of distinguishing parts made on the same process to the same specification. In summary, you want to select the parts in a way that represents the minimum sized part, the maximum sized part and those in between. If the selected parts have different specifications, they are different by design, not by random variation.

Question #2: “Results can be calculated in several ways: using study parameters, specifications and others. Which is most acceptable for gage R&R?”

Answer: The industry trend is to use study/process parameters, however, how you calculate the results of a gage R&R study depends on the purpose for doing the study. Before the study begins, you should decide what the primary purpose for conducting the study is. If you are trying to control your process, you need to be able to detect changes in the process. To do this, you should use study parameters or process parameters. If your focus is being able to compare a part to specifications, then you should use the specification method. Using the specification method suggests that you are trying to prove that your measurement system can distinguish between good and bad parts.

If you have any other questions or concerns about MSA or gage R&R, please contact us at support@pqsystems.com or by phone at 800-777-5060 or just post them below.

Like contests and challenges? You can put away your online copy of crosswords or Sudoku. Here’s one you can do from your desk without feeling guilty about wasting company time…

If you use CHARTrunner, or if you are evaluating CHARTrunner on a free trial basis, this will be a breeze for you. If you have a flare for design, you’ll love it.

Here’s how it works: Using a standard data set, simply create a CHARTrunner chart. Click here to download the data set or email us to request it. Sounds simple, right? Using CHARTrunner is, of course, the simplest aspect of this task. We encourage you to delve deeply into the data, and create a chart that helps others understand the data at a glance.

The second step is to email your chart to our panel of judges, who will award an iPod Touch for the best submission based on the following criteria:

1. the most informative chart;
2. the most aesthetically pleasing visualization;
3. the most surprising information illuminated from the data set.

To qualify to win your own iPod Touch, submit your chart, following these rules:

1. use only CHARTrunner and the supplied data (no additions); no touching up chart using Photoshop or other programs;
2. submit your chart file and the chart style file before July 15, the deadline for the contest;
3. agree to let us publish your chart in an issue of Quality eLine;

The panel of experts who will judge the entries include members of PQ Systems development team, design team, and marketing team, plus a current customer who is not employed by the company.

This is your chance to push your knowledge of CHARTrunner features to their limit, and to discover new ways of creating charts from the software.

Note: This contest is not open to PQ employees or their families.

Recalls of Toyotas (including Prius and Lexus models), news of quality issues that have halted use of 40 over-the-counter children’s drugs, an oil spill in the Gulf of Mexico that reveals failure of several back-up emergency systems, a mine collapse with evidence of negligence: all of these recent newsmakers highlight the critical importance of putting quality methods in place and being able to prove that systems to prevent failure are indeed sustained and working.

These systems are necessary to assure quality in products and processes, and when they involve potential loss of human life, this is even more true. How can a big company with multiple product lines assure the quality of its products and avoid recalls that are related to issues of quality? And how do companies communicate their concerns to customers in a timely way? These and other questions are raised by recent events.

What steps is your company doing to avoid these kinds of catastrophes?

What is known as “point mentality” is a knee-jerk response to what appears to be a problem. We may learn this when we take our child’s temperature and find that it’s high; we are inclined to do something right away—give ibuprofen, orange juice, and bed rest—rather than waiting to see if this is a “trend.”

In fact, sometimes we can’t wait to evaluate patterns in data, but need to respond immediately to a situation. Emergencies require response. But most of the time, we will save time, energy, and other resources by examining data over a period of time and making decisions based on trends or other patterns in the operation of the system itself. The fact that a child fails one third-grade spelling test does not mean that he or she will be a failure in life—or even in spelling.

Every system has variation; some of this is due to the system itself, known as common cause variation; some of it is due to singular incidents or special situations; this is special cause variation. W. Edwards Deming estimated that 94% of problems (or possibilities for improvement) lie with the system as common-cause variation; 6% are special causes. [Out of the Crisis, 315]

Describing variability over a period of time helps one to understand how the system is working, and to predict how it will continue to work in the future. The alternative is a constant tampering with the system, responding to every whim it may have.

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