I creat a design fmea about a electronic circuit.
We ask us, "is a short-circuit in electronic circuit" a failure effect or
a failure cause?

Have someone a idea?

regards Jim
:thanx:

Jim, in this site (http://www.mtain.com/relia/relfmeca.htm) the term is used as a Failure Mode.

This procedure (http://arioch.gsfc.nasa.gov/302/pdf/fmea.pdf) goes into more detail.

I creat a design fmea about a electronic circuit.
We ask us, "is a short-circuit in electronic circuit" a failure effect or
a failure cause?

Have someone a idea?

regards Jim
:thanx:

It could be either or both. If something else fails as a result of the short, it's a cause for that failure. If the short occurs as a result of failure of another component, it's an effect. How you characterize it depends on the overall scope of the analysis.

Jim 123,

As Jim Wynne suggests.

If you need some more detail, I have a design aid that I have attached for Design FMEA's.
Mike

I completely agree with Jim's comment on this.

In fact, you have to see this on a time line :

Cause - Failure - Effect.

Best regards,

Antoine

O.K. but I can't understand it 100%.
If i analyse the design of a electronic circuit diagram with resistor, capacitor, diode and s.o., what's the reason of failure modes?
resitor to small -> effect: resistor to hot -> effect: short circut.

I define the drawing resistor is o.k., my argument is the short circut resistor is a
process item.

Thank you for your idees!!!
Jim
:confused:

Well, I think,it depends on how detail you want to prepare fmeas.

A short could be how the failure mode shows it's self but that may mean that this is not the true nature of the faiulre but rather the effect of the failure.

As said before this could be down to a poorly specified component say basically you pay your money and you take your choice.

The key thing to remember is the types of failure mode can be classified into "no function" / "partial function" / "intermitent function" / "unintended function". If the short does not fall into one of these then it is the effect of the failure mode or possibley the cause. Personally I would say this:
The circuit failed to function this was because the XYZ failed due to a short in the cuircuit hence in this case the short is the cause. To run the potential cause down use the 5 why method. Just use logic and when all the improbable answers have been excluded the one left no matter how stupid it looks is the answer.