MSA training - gage acceptance and measurement system analysis according to MSA manual (AIAG)
What will you learn on this MSA training course?
When SPC (Statistical Process Control) was introduced in industrial production in the early 1980s, it was accompanied by worker self-inspections. Workers were responsible for the quality of the parts they produced. In order to be able to evaluate the characteristics of the parts produced, so-called SPC measuring stations were established close to the production line. Capability studies were carried out to assess the measuring devices (gages) in order to verify their suitability for the specific application (gage capability or inspection equipment capability).
The AIAG’s MSA (Measurement Systems Analysis) manual, which has been continuously improved over the years and used as the basis for company guidelines, was
groundbreaking in terms of the approach taken. A guideline issued by the German automotive industry introduced further statistics for evaluating the measuring system. This MSA training course introduces you to the approaches to gage acceptance and provides you with the necessary facts, basics and procedures. You will learn about all the procedures and statistics required to evaluate a measuring system or measurement process.
In this MSA training course, you will learn how to prove the measurement system capability of measuring systems in accordance with the AIAG MSA Manual. You will evaluate measuring equipment using statistics such as Cg, Cgk and %GRR, carry out Type-1, Type-2 and Type-3 studies and evaluate the capability of measurement processes for use in industrial production and manufacturing.
The MSA training on gage acceptance in detail
Evaluation of the measuring system:
- Typical influence quantities
- Evaluating the resolution
- Calibration uncertainty
- MSA type-1 study
- Linearity analysis
- Calculating the capability indices Cg, Cgk
- Transferability of the results
Evaluation of the measurement process:
- Typical influence quantities
- MSA type-2 study or type-3 study
- Calculating the statistics %EV, %R&R, %GRR
- Stability analysis
- Dealing with measurement processes that are not capable
Further information
What does measurement system analysis (MSA) mean?
MSA stands for measurement system analysis, a systematic investigation that assesses whether a measurement or inspection process produces reliable, accurate and repeatable results.
It is not the product that is tested, but solely the measuring system itself: the measuring instrument, the operator, the measurement procedure and the environmental conditions. The aim is to demonstrate that the measuring system is suitable for the respective measurement task.
What does the MSA analyse?
An MSA typically considers the following statistics of the measuring system:
- Repeatability: Does the same measuring system produce comparable results under the same conditions?
- Reproducibility: Do the results match when different operators take the measurements?
- Bias: Is there a systematic deviation from the true value?
- Linearity: Is the measurement accuracy consistent across the entire measurement range?
- Stability: Will the measuring system remain reliable over time?
However, MSA has two different meanings.
On the one hand, MSA refers to measurement system analysis as a method, that is, the systematic analysis of a measurement process.
Secondly, MSA stands for the MSA Manual published by the AIAG (Automotive Industry Action Group). This reference manual, currently in its 4th edition, defines the established methods for evaluating measuring systems in the automotive industry and is a key component of quality assurance under IATF 16949.
How do you accept gages?
The capability of inspection equipment is demonstrated by means of a measurement system analysis (MSA). This includes the following procedures:
Type-1 study is used by manufacturers of measuring equipment to prove that a measuring system is capable of performing a specific task. In this context, measuring system is synonymous with the measuring or inspection equipment (gage) itself. Type-1 study according to the MSA Manual determines whether the measuring equipment measures accurately even when being affected by possible influence quantities and whether the measurement results are repeatable. Any operator or apparaiser influence is not taken into account. Only after this study has been completed are measuring instruments shipped or installed. Typical statistics are Cg and Cgk.
Type-2 study and type-3 study evaluate the measuring system under real operating conditions. Type-2 study evaluates new and existing measuring equipment prior to final acceptance at the plant, taking into account all influence quantities, including operator influence. Typical statistics are %EV, %R&R or %GRR.
Type-3 study is a special case of type-2 study and is used for fully automatic measuring systems when all influence quantities except appraiser influence are effective in real use.
MSA type-1, type-2 and type-3 studies are all explained in this training course.
Wann ist eine Messsystemanalyse (MSA) notwendig?
A measurement system analysis is used to check whether a measuring system is capable to fulfill its intended purpose and delivers reliable results. Without this analysis, measuring systems may be subject to large variations or provide systematically incorrect measurement values, meaning that genuine process deviations often go undetected.
As a rule, a measurement system analysis is used in the following cases to prove the capability of the inspection equipment
- when purchasing new measuring systems or setting up new measuring systems
- to evaluate existing measuring systems
- if there are doubts about the quality or correctness/accuracy of the measurements
- in the event of changes to the measurement process or the product
- to meet general standards or customer requirements
What do linearity and stability mean?
Linearity describes the change in bias over the total operating range of the measuring system. A linearity study determines whether a measuring system measures with the same accuracy across the entire measuring range and does not, for example, deliver very accurate values for small measured values but shows significant deviations for large measured values.
Stability describes the change of bias over time. A stability study determines whether the measurement results of a measuring system show time-dependent changes or not, i.e. today’s measurement results should be just as accurate as those recorded by the measuring system in a week’s time.
