Process FMEA - Should FMEA be done for all processes?

[Andrews]

The process sequence of a particular part is
a) Turning
b) Counterboring
c) Tapping
d) surfcae coating
Should FMEA be done for all these processes or can we restrict it to those operations that have parameters that affect safety,function,next operation etc.

 

[Ravi Khare]

Should FMEA be done for all these processes or can we restrict it to those operations that have parameters that affect safety,function,next operation etc.

I suppose you will find out whether the operations have such type of parameters only after you do FMEA on these operations.

 

[D.Scott]

Ravi's point is well made. You should look at every step in your process, however if there is truly no failure mode, you would have no need to address it.

You should, in your FMEA preperation, consider all failure modes regardless of the effect on the parameters you specified.

Dave

 

[db]

Failure Modes

You should, in your FMEA preperation, consider all failure modes ...

Dave,

How do you feel about failure modes in relation to items such as scrap, environmental performance, change over times, and other non-traditional process FMEA failure modes? Should they be included as well? If so, how far do you take it?

 

[D.Scott]

Good question Other Dave. I haven't considered scrap as a failure mode, more as a result of failure. The environmental issues have been addressed up front and again would appear on the FMEA as a result rather than a failure mode. I can see where change over could be a cause of failure but I struggle to see it as a failure in itself. This is certainly not to say I am right.

I guess we are up against the old "depends on the process" discussion as to how deep you should go on the FMEA. Personally, I would like to keep them as simple as possible while covering the needs of the customer. Then again, there are customers and then there are CUSTOMERS.

Dave

 

[Andrews]

Process FMEA methodology

We have been addressing the severity of failures in terms of its function, usability etc.For e.g if variation in a particular dimension is found not to affect the function,we state the effect as "no effect on function" and rate the severity as 2.

During one of our customer's visit,he was urging us to address the effect in terms of its acceptance i.e scrap or rework etc.in addition to functional aspect.

Is the customer's stand right?

 

[Ravi Khare]

It will be for your own good to address scrap and rejection, inspite of whether the customer's stand is right or otherwise.

 

[Andrews]

severity ranking

What should be the severity rating for "customer rejection"? We have specified a severity rating of 5 for customer rejection.