Six Sigma For Dummies, 2nd Edition

Chapter 14

Gauging Gauges: Measurement System Analysis (MSA)

In This Chapter

Understanding variation that comes from the act of measuring

Speaking the language of measurement system analysis

Using audits, attribute studies, and gauge studies

With all the attention on data capture and analysis in Six Sigma, you may be prone to overlook the quality of the measurement systems you use to capture the data in the first place. But data form the foundation of your knowledge and decisions; imagine what would happen if all your analysis and conclusions were based on faulty data. Garbage in, garbage out.

In this chapter, we show you how to use a measurement system analysis — or MSA, as it’s usually called — to quantify how much observed variation is coming from the measurement system itself. You must be able to immediately eliminate any chance that the measurements you’re using are creating an illusion.

Avoiding Illusion: Measurement System Capability Analysis

Measurement is critical. It’s the foundation of knowledge and of subsequent improvement. You measure to find the problem, and you measure to verify that you have the right answer, have corrected the problem, or have improved the situation. ...