MSA training - gage acceptance according to MSA Manual (AIAG) and company guidelines
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.
Our 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 MSA mean?
MSA has two different meanings.
MSA refers to the MSA Manual (Measurement Systems Analysis) of the AIAG (Automotive Industry Action Group). The current 4th edition is considered the reference manual for the assessment of measuring systems (measuring and inspection equipment or gages) in the automotive industry and is part of quality assurance according to IATF 16949. This manual forms the basis of this MSA training course.
On the other hand, MSA stands for measuring system analysis. This is the systematic examination of a measurement process with the aim of proving the capability of the measuring system to fulfill the respective measurement task. It is not the product that is evaluated, but exclusively the measuring system itself.
When do you need MSA?
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
Which types of MSA studies are there?
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.
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. 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.
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.
