AIAG MSA (Measurement Systems Analysis) Manual 3rd ed. Chapter IV

[Southern Cross]

From Section A, stability studies S1 and S2 can be done for situations where "the shelf life of the characteristic is known and extends beyond the expected duration of the study".

I'm uncertain of the terms used. What constitutes a cycle? Is it time based?

Where is S1 (single part, single measurement per cycle) used compared with S2 (n >= 3 parts, single measurement per cycle per part).

 

[Stijloor]

From Section A, stability studies S1 and S2 can be done for situations where "the shelf life of the characteristic is known and extends beyond the expected duration of the study".

I'm uncertain of the terms used. What constitutes a cycle? Is it time based?

Where is S1 (single part, single measurement per cycle) used compared with S2 (n >= 3 parts, single measurement per cycle per part).

Can someone help our Member?

Thank you!!

Stijloor.

 

[Miner]

Interesting that AIAG failed to define this. I searched throughout this section and it is not defined. From the context and my experience, I would say that it appears to imply a complete measurement cycle. rather than ant type of manufacturing cycle. Non-replicable measurements tend to be associated with more complex measurement instruments that have distinct cycles.

S1 would typically be used for difficult, time consuming tests while S2 would be used for quick and easy tests.

 

[Southern Cross]

Non-replicable measurements tend to be associated with more complex measurement instruments that have distinct cycles.

Miner, thanks for clearing up the S1 vs. S2 question.

Details of the instrument in question are in the attached pdf file. I still don't understand the concept of a measurement cycle. Can you expand on that? Or give an example?

 

[Southern Cross]

Thinking about the measurement cycle, the instrument would typically be turned off at night and on again in the morning. Maybe the tests should be done daily?

 

[Miner]

I am not familiar with this type of test equipment. Does it provide continuous test results as product runs through it?

A test cycle is not the same as a power down/up cycle. A test cycle is the time that it takes to perform a single complete test. I believe that the reason that it is specified in this fashion is because some tests will take many readings of a single test sample then average them to obtain a single test result.

 

[Southern Cross]

A set quantity of product (viscous fluid) is applied to the bottom rubber roller. The time for a test is only 60 seconds after the sample is applied. Clean up of the rollers takes much longer. The whole test process is about 10 minutes.

I'm afraid the industry I work in has not been at the forefront of quality management, to put it mildly. I don't think I'm going to have the clout to make people do a calibration check with every sample test. Daily might be a chance. A set of multiple tests daily might be a chance.