DFMEA Detection Ranking in AIAG FMEA Manual 4th Ed. - Explanation wanted

[manishpawar]

Can someone explain the detection ranking in the new version of DFMEA i.e version 4.

what is the difference between testing for failure and degradation testing.

[Larry Preuett]

In Reply to Parent Post by manishpawar

Can someone explain the detection ranking in the new version of DFMEA i.e version 4.

what is the difference between testing for failure and degradation testing.

Hello, I'm not familiar with the particular s/w package that you are using, however I have plenty of FMEA experience and the concepts are all the same.
Here's a simple explanation of the difference:

Testing for failure = When I turn the switch to the "on" position does the green light come on and does the wheel start spinning as it is supposed to. In other words challenging the device to confirm that it operates per specification as advertised to your customers.

Degradation testing = challenging the product to determine its reasonable life expectancy. An example, drug companies have to challenge their product to determine its expiry date, meaning the earliest date on which the product might no longer meet specification.

Hope this helps.

Larry

[Stijloor]

In Reply to Parent Post by Larry Preuett

Hello, I'm not familiar with the particular s/w package that you are using, however I have plenty of FMEA experience and the concepts are all the same.

Larry,

The OP is referring to the AIAG FMEA 4th Ed. manual, not a software package.

The detection ranking table that he is mentioning is located on page 54.

Stijloor.

[Stijloor]

In Reply to Parent Post by manishpawar

Can someone explain the detection ranking in the new version of DFMEA i.e version 4.

What is the difference between testing for failure and degradation testing.

Testing for failure can be a destructive test on a part, sub system or system.

Degradation testing can be an accelerated salt-spray test to verify corrosion resistance.

Stijloor.

[manishpawar]

thanks larry for caring to answer,

but as stijloor says its not a software package,i am refering to the AIAG FMEA manual.

As u said stijloor the exercise of DFMEA is conducted for a automobile scissor jack.

can u explain it respect to a scissor jack,

the function is to lift the vehicle of a specified load to a specified height, with a max speciifed torque.

The jack is subjected to a test for a certain cycles (10000 cycles)for lifting and descent.

what can degradation test and testing for failure be in this case.

[Jim Wynne]

In Reply to Parent Post by manishpawar

thanks larry for caring to answer,

but as stijloor says its not a software package,i am refering to the AIAG FMEA manual.

As u said stijloor the exercise of DFMEA is conducted for a automobile scissor jack.

can u explain it respect to a scissor jack,

the function is to lift the vehicle of a specified load to a specified height, with a max speciifed torque.

The jack is subjected to a test for a certain cycles (10000 cycles)for lifting and descent.

what can degradation test and testing for failure be in this case.

In general, failure applies to primary function and degradation applies to diminished functionality. In other words, your scissor jack might fail completely, meaning it's no long capable of performing its primary function, or its function might diminish with continual use such that it will still perform its primary function but not as well as when new.

[manishpawar]

thanks jim

i will try to buildup the concept on yours and stijloor's inputs.

Will summarize it and post it the earliest.