What is MSA?
Learn More about MSA with this Tutorial:
What is a Measurement System?
Measurement system is the collection of instruments or gages, standards, operations, methods, fixtures, software, personnel, environment and assumptions used to quantify a unit of measure or fix assessment to the feature characteristic being measured; the complete process used to obtain measurement
What is MSA?
Measurement System Analysis (MSA)
- MSA primarily deals with analyzing the effect of the measurement system on the measured value
- The objective of MSA is to assess the quality of the measurement system
We test the measurement system to:
- determine its statistical properties, and use them in comparison with accepted standards, our needs and customer requirements
Measurement System Analysis
To evaluate a measurement system, determine:
- If it has adequate resolution
- If it is statically stable over time
- If statistical properties are consistent over the expected range and acceptable for process analysis of control
- If the sum of all the variables is an acceptable level of measurement uncertainty.
Measurement System Analysis Continued
Uncertainty of Measurement
- The range within which the true value of a characteristic is estimated to lie
- Can be expressed as statistical distribution of a series of measurements, standard deviations, probability, percentages, error as the difference between actual value minus the true value as a point on a control chart or diagram, etc.
Measurement Knowledge to be Obtained
- How big is the measurement error?
- What are the sources of measurement error?
- Is the measurement system capable for this study?
- How do we improve the measurement system?
Implementing Good Measurement Systems
- Identify all inspection, measuring and test equipment (IMT) and show calibration status
- Ascertain accuracy and precision of IMT
- Conduct variation studies of IMT (MSA)
- Determine validity of previous results when IMT is found out of calibration
Implementing Good Measurement Systems Continued
- Establish comprehensive procedures for handling, preservation, cleaning, maintenance and storage of all IMT
- Records of calibration shall include employee gages
- Use all criteria of MSA
PPAP, 4th Edition-MSA Requirements
2.2.8 Measurement System Analysis
- shall include bias, linearity, stability and Gage R&R studies for ALL new or modified gages, test and measuring equipment
Application of MSA
Practical Sense of MSA Requirements
- What is in the Control Plan?
- Does it cover Process and Product Parameters?
- Does it cover IMT from incoming to shipping?
- Does it cover end of line and requirements for downstream activities?
- Does it cover lab equipment used for testing and analysis?
- Does it cover IMT for characterization and validation testing?