Meaning of Control/Detection in FMEA??

[Guillaume Stollman]

What is the meaning of Control/Detection in the FMEA-template? Some consider tests that are performed during development (before actual release of the product) a good form of detection. I have some difficulty with that. In my opinion detection says something about how able you are to detect the failure mode (or root cause) once it occurs, before the customers sees the effect. Verifcation (or other) tests in development are never able to do that, as they do not test the actual product the customers is going to received (or has received). Tests in development are to verify the design, and therefore help to reduce the probability of occurence of the failure mode (or root cause) happening. Detection is about detecting the actual failure mode (or root cause) early before the effect is seen by the customers. Those detections can only be done by e.g. production tests, extras tests in the field (e.g. by preventive maintenance, etc). At least this is my opnion.

How do others handle control/detection in an FMEA??

Guillaume Stollman
Philips Healthcare

[Brendan O'Byrne]

Hello.
I interpret these fields in FMEA as design or process control prevention and design or process control detection. How they are described depends on whether you are in a Design FMEA (DFMEA) or Process FMEA (PFMEA).

If we take the DFMEA case in the first instance.
If the part is to meet a certain function and be robust against a certain cause of failure or noise factor, the Design Control Prevention enables the description of how the part has been designed to meet these criteria. The Design Control Detect then allows us to describe how we will test this design and the confidence we have that this test would find any potential failure mode(s) about which we are concerned. This test would be part of by DV or Design Verification plan.

For a PFMEA, the procedure is the same, except that the various sub processes which support the process under discussion will be described. And under the process control detection, tests to ensure that that this process has been completed successfully can be entered. An end of line test could be referenced as one of these tests. These would be the tests that would check for parts which have not been manufactured as required in the design and as such prevent 'bad' parts going to the customer.

I hope this helps.
All the best,
Brendan O'Byrne
Keltech Design