Potential Failure Mode - Machine Stroke not in specification

wanamir · May 19, 2006

I need somebody to help me with the PFMEA where the condition as below.

Function : Machine Setting
Potential Failure Mode : Machine Stroke not in specification
Potentail Effect of failure : Product Emboss out of specification
Potential Cause of failure : Machine Parameter not correct

From the above condition, can I take "Product Emboss out of specification" as a Potential Failure Mode at the subsequent process.

Function : Set Up Inpection
Potential Failure Mode : Product Emboss out of specification
Potentail Effect of failure : Customer critical point NG / Customer Rejection
Potentail Cause of failure : Machine Stroke not in specification

Stephanie · May 19, 2006

Some comments for sharing:
Since you mentioned this is a function for "Setup Inspection", I'd like to ask and clarify for below doubts:
1)Potential failure mode:what kinds of out of spec? emboss too big? too deep?
2)Potential effect of failure: Is there any direct impact to the end user, cause this could be categorized as poor appearance. In case your customer is the next operation or subsequent operation(s)/location(s), there will be effects like "cannot be match with mating devices"
3)Potential cause/mechanism of failure:besides machine stroke not within spec, could it be due to improper machine setup?

Stephanie · May 19, 2006

Amir,
A gentle advice: beware for unnecessary typo error.

Jim Wynne · May 19, 2006

wanamir said:
I need somebody to help me with the PFMEA where the condition as below.

Function : Machine Setting
Potential Failure Mode : Machine Stroke not in specification
Potentail Effect of failure : Product Emboss out of specification
Potential Cause of failure : Machine Parameter not correct

From the above condition, can I take "Product Emboss out of specification" as a Potential Failure Mode at the subsequent process.

Function : Set Up Inpection
Potential Failure Mode : Product Emboss out of specification
Potentail Effect of failure : Customer critical point NG / Customer Rejection
Potentail Cause of failure : Machine Stroke not in specification

If I understand the question correctly, you are asking: If some failure mode x is considered in operation a, is it necessary to address the same failure mode in operation b?

The answer is "no." Material entering a process or operation should be considered "good," and you should focus on the potential failure modes of the process at hand. The only exception is receiving inspection, where it can't be assumed that incoming material is acceptable (otherwise there'd be no need for receiving inspection).

Bill Ryan - 2007 · May 19, 2006

wanamir said:
Function : Set Up Inpection
Potential Failure Mode : Product Emboss out of specification
Potentail Effect of failure : Customer critical point NG / Customer Rejection
Potentail Cause of failure : Machine Stroke not in specification

A question I have for you - Is a product characteristic being out of specification really a Failure Mode of an Inspection Action step?

wanamir · May 22, 2006

Stephanie said:
Some comments for sharing:
Since you mentioned this is a function for "Setup Inspection", I'd like to ask and clarify for below doubts:
1)Potential failure mode:what kinds of out of spec? emboss too big? too deep?
2)Potential effect of failure: Is there any direct impact to the end user, cause this could be categorized as poor appearance. In case your customer is the next operation or subsequent operation(s)/location(s), there will be effects like "cannot be match with mating devices"
3)Potential cause/mechanism of failure:besides machine stroke not within spec, could it be due to improper machine setup?

Thank you for your comments.
These are the answers for your doubts.

1. Potential failure mode : Emboss Too Deep
2. Potential effect of failure : Happen at subsequent operation; Assembly or mating problem.
3. Potential cause/mechanism of failure : Machine stroke not according to tooling standard stroke.

Sorry for the typing errors.

wanamir · May 22, 2006

Jim Wynne said:
If I understand the question correctly, you are asking: If some failure mode x is considered in operation a, is it necessary to address the same failure mode in operation b?

The answer is "no." Material entering a process or operation should be considered "good," and you should focus on the potential failure modes of the process at hand. The only exception is receiving inspection, where it can't be assumed that incoming material is acceptable (otherwise there'd be no need for receiving inspection).

----------------------------------------------------------------------
Function : Machine Setting
Potential Failure Mode : Machine Stroke not in specification
Potential Effect of failure : Product Emboss out of specification
Potential Cause of failure : Machine Parameter not correct

From the above condition, can I take "Product Emboss out of specification" as a Potential Failure Mode at the subsequent process.

Function : Set Up Inspection
Potential Failure Mode : Product Emboss out of specification (Emboss too Deep)
Potential Effect of failure : Customer critical point NG / Customer Rejection
Potential Cause of failure : Machine Stroke not in specification
-----------------------------------------------------------------------
Again this is my question. You see at the first process I took " Product Emboss out of specification (Emboss too deep)" as a Potential effect of failure.
But now in "Set Up Inspection" process, our customer, Bosch required us to included the claim of "Emboss too Deep" as a "Potential Failure Mode" since this point is their CTC point (Critical To Customer). Now you see this "Emboss too Deep" is available in two kind of form, first as Potential Effect of Failure and also "Potential Failure Mode".
It is correct or not?

Jim Wynne · May 22, 2006

wanamir said:
----------------------------------------------------------------------
Function : Machine Setting
Potential Failure Mode : Machine Stroke not in specification
Potential Effect of failure : Product Emboss out of specification
Potential Cause of failure : Machine Parameter not correct

From the above condition, can I take "Product Emboss out of specification" as a Potential Failure Mode at the subsequent process.

Function : Set Up Inspection
Potential Failure Mode : Product Emboss out of specification (Emboss too Deep)
Potential Effect of failure : Customer critical point NG / Customer Rejection
Potential Cause of failure : Machine Stroke not in specification
-----------------------------------------------------------------------
Again this is my question. You see at the first process I took " Product Emboss out of specification (Emboss too deep)" as a Potential effect of failure.
But now in "Set Up Inspection" process, our customer, Bosch required us to included the claim of "Emboss too Deep" as a "Potential Failure Mode" since this point is their CTC point (Critical To Customer). Now you see this "Emboss too Deep" is available in two kind of form, first as Potential Effect of Failure and also "Potential Failure Mode".
It is correct or not?

First, as someone else has already pointed out, Inspection can't cause defects, so the second example is fundamentally wrong in that regard.
As to whether it's correct to use the same condition twice in consecutive operations, reread my first response. It should be assumed that the condition was dealt with upstream, and in the second instance you should be concentrating on potential failure modes that are caused in that operation. In this instance, with the second example, you should be addressing the implications of potential failures of the setup inspection process, which include (among other possibilities)accepting "bad" material or rejecting "good" material. In this sense, all potential failures should be considered, including embossing errors, especially if embossing is a critical characteristic.

To put it more plainly, in your second operation, the potential failure mode should not be tied to upstream processes--it should be characterized as a failure of the inspection process.

Potential Failure Mode - Machine Stroke not in specification

wanamir

Stephanie

Registered Visitor

Stephanie

Registered Visitor

Jim Wynne

Bill Ryan - 2007

wanamir

wanamir

Jim Wynne

Similar threads