MSA | MSA meaning | MSA full form | MSA in Quality

MSA stands for Measurement System Analysis.

MSA helps to understand the sources of variation that influence the measurement result produced by the measurement system.

MSA is one of the very important core tools of the IATF 16949:2016 standard and widely used in Statistical Process Control and problem-solving tools like 8D, and Six Sigma-DMAIC methodologies.

The five IATF Core Tools are: APQP, FMEA, PPAP, MSA, and SPC.

MSA core tool is a part of APQP planning and one of the important document of the production planning approval process (PPAP).

MSA Meaning | Definition | Purpose

MSA primarily deals with investigating/analyzing the effect of the measurement system on the measured value.

Let’s understand the meaning of important terms used in the MSA quality core tool.

Measurement is defined as the assignment of numbers to material things to represent the relationship with respect to particular properties.

The measurement system is the collection of operations, Gages, and Equipment, Environment and personnel used to assign a number to the characteristic being measured.

The measurement process should be viewed as a manufacturing process that produces numbers (data) for its output.

Measurement System analysis study is carried out to determine the amount of variation or error present in the collected/measurement data due to measurement system.

No two things are alike in the world, there may be some variation. Variation is the law of nature and it can’t be eliminated but reduce to a controllable limit to achieve desired results.  

The major sources of variation are broadly classified into two categories:

• Measurement System Variation-MSV.
• Manufacturing Process variation-MPV.

MSA’s purpose is to find the Measurement System Variation only.

It is very important to note that MSV should always be smaller than MPV (MSV<MPV).

The measurement system variations mainly focus on two important factors:

• Equipment variation (within system variation)-known as Repeatability.
• Appraiser variation (between system variation)-known as Reproducibility.

In the measurement system analysis, the Gage R&R study tool is conducted to find out the equipment variation and appraiser variation.

Measurement System Distribution | Variations

MSA classified into 2 types of distributions:

1. Location distribution
   • Stability
   • Bias
   • Linearity
2. Width or spread
   • Repeatability
   • Reproducibility

MSA in Quality

The objective of MSA in Quality or Measurement Process is to:

PRODUCT CONTROL

• Whether the product meets the specification requirements?

PROCESS CONTROL

• Is the process variation stable and acceptable?

MSA in Quality-Example

To measure the inside diameter of a cylindrical hole, we use a system that Includes:

• Item of Interest
• Personnel
• Measurement Equipment
• Method to use the Equipment
• Environment under which to conduct the measurement

As a result of the activity, we generate a numerical value that represents the diameter.