Measurement System Analysis (MSA)

Description
The goal of the measurement system analysis is to Evaluate the variation generated by the measurement system which must be small compared to the actual variation between parts and compared to the specifications of the Product.



This is a practical guide for the essentials that you should know about measurement system analysis (MSA) in accordance with the 4th edition of the AIAG manual.


Table of contents:
• What is a measurement system and why should it be evaluated?
• History of measurement system analysis
• The main characteristics of a Measurement System
• The different types of R&R studies
• Crossed R&R study: Methods, process and interpretation of results
• Attribute Agreement Analysis: Process and interpretation of results
• Attribute Gage Study: Process and interpretation of results


As with any process, the measurement of a product characteristic or a process parameter can record a variation. This Observed variation in measured values is the combination of two variation:

• Actual variation between parts
• Variation caused by the measurement system


If the variation caused by the measurement system is important, then the measurements will be false and will not represent the actual values of what we want to measure. This may cause a bad decision making.


The methods of analyzing a measurement system differ depending on whether we are dealing with continuous or attribute data.