My field is microelectronics.
I know the definition written in the APQP book:

Characteristics:
19) "Product - features or properties of a part, component or assembly that are described on drawings or other primary engineering information.

20) Process - process variables that have a cause and effect relationship with the identified Product characteristics."


PF steps:
1) Wafer fabrication (Sub-contract)
2) Incoming inspection wafer
3) Probing (Chip Test)
4) Off-line inking
5) Outgoing Inspection Wafer
6) Wafer packaging
7) Shipping
8) Assembly (Sub-contract)
9) Inspection assembled devices
10) Final Test
11) Outgoing Inspection QCel
12) Outgoing Inspection assembled devices
13) Packaging and shipping

I'm not so confident about what to put in each column.
I'm not sure what is the difference between process and product related characteristic.

Are all process characteristics variables only? What about the attributes?

:confused:

Our "methodology" is very simple -

From the PFMEA - The Failure Mode goes in to the Product Characteristic Column and the Failure Cause goes in to the Process Characteristic column. However, there is no Process Characteristic in the Control Plan unless there is a Prevention Control in place addressing that Failure Cause.

Does that make sense - or help any?

My field is microelectronics.
I know the definition written in the APQP book:

Characteristics:
19) "Product - features or properties of a part, component or assembly that are described on drawings or other primary engineering information.

20) Process - process variables that have a cause and effect relationship with the identified Product characteristics."


PF steps:
1) Wafer fabrication (Sub-contract)
2) Incoming inspection wafer
3) Probing (Chip Test)
4) Off-line inking
5) Outgoing Inspection Wafer
6) Wafer packaging
7) Shipping
8) Assembly (Sub-contract)
9) Inspection assembled devices
10) Final Test
11) Outgoing Inspection QCel
12) Outgoing Inspection assembled devices
13) Packaging and shipping

I'm not so confident about what to put in each column.
I'm not sure what is the difference between process and product related characteristic.

Are all process characteristics variables only? What about the attributes?

:confused:

It's really pretty simple. Product characteristics are attribute and variable characteristics of the part. Process characteristics are the features/aspects of the process (machine settings, "feeds and speeds," e.g.) that must be controlled in order to achieve the desired state of the product characteristic. IMO, there should never be a product characteristic listed without a corresponding process characteristic (or characteristics, there might be more than one for each product characteristics).

Remember--it's not an inspection plan, it's a process control plan.

It's really pretty simple. Product characteristics are attribute and variable characteristics of the part.

However - a product of the process could be one of the "process measureables" and not, necessarily, a dimension on a part.

However - a product of the process could be one of the "process measureables" and not, necessarily, a dimension on a part.
I'm not sure I understand what you're saying, but I think I disagree. :D
The product is the product--the part being made, or whatever it is that's being transformed by the process. I think it's important to maintain a clear distinction between the thing being worked on and the work being done on it. I think that's the whole idea behind the bifurcation. That being said, if you have a method that works well for you, and good reason for creating distinctions outside of the basic framework, then that's what you should do.

It's really pretty simple. Product characteristics are attribute and variable characteristics of the part. Process characteristics are the features/aspects of the process (machine settings, "feeds and speeds," e.g.) that must be controlled in order to achieve the desired state of the product characteristic. IMO, there should never be a product characteristic listed without a corresponding process characteristic (or characteristics, there might be more than one for each product characteristics).

Remember--it's not an inspection plan, it's a process control plan.

Thank you Jim! As usual - very accurate and clear explanation.
Can you list some examples: links product - process characteristics please!

Within my organization the link is as like this:

Product characteristic -> Process characteristic(s) impacting product characteristics -> Adjustment items (operator control paramenters) -> control limits -> corrective action

I work for a steel company - a tad more dirty than yours, Brutas (or so I assume). ;)

Prod. char = Grade of steel
Proc. char = Alloys, addition of
Adj. Items = Qty.
Control Limits = As per steel recipe
Corrective action = As per QC technician

A generic and simple example, but that's how we've basically aligned things.

Any other examples? :rolleyes:

Within my organization the link is as like this:

Product characteristic -> Process characteristic(s) impacting product characteristics -> Adjustment items (operator control paramenters) -> control limits -> corrective action

I work for a steel company - a tad more dirty than yours, Brutas (or so I assume). ;)

Prod. char = Grade of steel
Proc. char = Alloys, addition of
Adj. Items = Qty.
Control Limits = As per steel recipe
Corrective action = As per QC technician

A generic and simple example, but that's how we've basically aligned things.

If I understand the process correctly, "Alloys, addition of" is a step in the process, or an operation, not a process characteristic. What process characteristics must be controlled when adding alloys?

Any other examples? :rolleyes:

Let's say the process is electroplating. Some of the product characteristics might be:

Substrate cleanliness
Deposit thickness
AppearanceFor each of those product characteristics, the process characteristics might be (in the same order)

Constituency, temperature and time for the cleaning bath
Dwell time, electrical current and rack position
Dwell time, current, rack position, bath contamination (or lack thereof) and chemical constituencyThis is oversimplification, but the point is that you start out with the requirements for product conformance (the relevant product characteristics) and then determine how you will control the process to achieve the desired results.

I used to work at a place that made clutch plates.

Process: Apply glue to raw steel core.

Product Characteristic: glue thickness
Process Characteristic: glue viscosity, oven temperature, oven cycle time.

Process: Bond friction material to steel core.

Product Characteristic: clutch plate thickness
Process Characteristic: bonder platen temperature, bonder platen pressure, bonder cycle time.

I used to work at a place that made clutch plates.

Process: Apply glue to raw steel core.

Product Characteristic: glue thickness
Process Characteristic: glue viscosity, oven temperature, oven cycle time.

Process: Bond friction material to steel core.

Product Characteristic: clutch plate thickness
Process Characteristic: bonder platen temperature, bonder platen pressure, bonder cycle time.

Excellent examples. :agree1:

:) My field is microelectronics.
I know the definition written in the APQP book:

Characteristics:
19) "Product - features or properties of a part, component or assembly that are described on drawings or other primary engineering information.

20) Process - process variables that have a cause and effect relationship with the identified Product characteristics."


PF steps:
1) Wafer fabrication (Sub-contract)
2) Incoming inspection wafer
3) Probing (Chip Test)
4) Off-line inking
5) Outgoing Inspection Wafer
6) Wafer packaging
7) Shipping
8) Assembly (Sub-contract)
9) Inspection assembled devices
10) Final Test
11) Outgoing Inspection QCel
12) Outgoing Inspection assembled devices
13) Packaging and shipping

I'm not so confident about what to put in each column.
I'm not sure what is the difference between process and product related characteristic.

Are all process characteristics variables only? What about the attributes?

:confused:

Dear friend ,

If I assume your product as an electronic assembled component.
These requires some process as mentioned above.
Like for ex wafer Packaging ,
If the output of this process is packaged item with certain conditions as per your standards.

These standards for this process becomes the Product attributes.
the opposite of these or not achieving these standards is called as Failure mode.
Now the causes are not only process paramters , but can be problem of the material you use , human erros , so on and so forth which are all arrived at based on the techincal brain storming and validation of these causes.

So FMEA is more or less common sense approach to eavluate the causes and their effect on failure of the product.

Hope I have made some point here.

thank You
Pratishesh.

:bigwave:

I am working In inkjet cartridge bottle assembly plant:
am i doing the right thing in my Cp?

Process: Filter Welding

Product char: No bent filter
Process Char: No mis aligned filter during robot picking

or should it be:?

Product char: Bent filter
Process char: mis aligned filter during picking

:thanks:

I am working In inkjet cartridge bottle assembly plant:
am i doing the right thing in my Cp?

Process: Filter Welding

Product char: No bent filter
Process Char: No mis aligned filter during robot picking

or should it be:?

Product char: Bent filter
Process char: mis aligned filter during picking

:thanks:

Hello 6sigmaBBsphinx,

A Product Characteristic is typically expressed in terms of something that is required and/or desirable. Such as in your example: "No bent filter."

A Process Characteristic is something associated with the PROCESS that must be controlled to prevent "bent filters" from happening. Your Process FMEA, should give you that information.

Also, look at the excellent posts in this thread.

Hope this helps.

Stijloor.

Hello 6sigmaBBsphinx,

A Product Characteristic is typically expressed in terms of something that is required and/or desirable. Such as in your example: "No bent filter."

A Process Characteristic is something associated with the PROCESS that must be controlled to prevent "bent filters" from happening. Your Process FMEA, should give you that information.

Also, look at the excellent posts in this thread.

Hope this helps.

Stijloor.


Does it basically means that i should put it like this:

Product char: No bent Filter
the corresponding Process Char: Alignment of Filter during Robot picking

or what specific area in the PFMEA that describes the Process Characteristics?

I get the product characteristic from Potential Failure mode

Does it basically means that i should put it like this:

Product char: No bent Filter
the corresponding Process Char: Alignment of Filter during Robot picking

Yes, I believe so. Feel free to provide more examples if you wish.

Once the Control Plan is in place, continuous monitoring of the process will show if you selected the correct process characteristic.

Stijloor.

Heres another Example:

Process: Barcode Application

Product Char: No mis aligned Barcode

Process Characteristics: Defective Tamp cyliner

please comment

Heres another Example:

Process: Barcode Application

Product Char: No mis aligned Barcode
Process Characteristics: Defective Tamp cyliner

please comment

What do you do in the PROCESS to PREVENT mis-aligned barcodes?

For example, does someone verify the "tamp cylinder" at a defined frequency?
Is there something in, or on the machine that prevents this?

What do you do in the PROCESS to PREVENT mis-aligned bar codes?

For example, does someone verify the "tamp cylinder" at a defined frequency?
Is there something in, or on the machine that prevents this?

The defective tamp cylinder was the Potential cause of failure as being called out in the PFMEA.. and the current control is Preventive Maintenance.

Where in PFMEa should i refer for the Process Characteristics?:(:(

Where in PFMEa should i refer for the Process Characteristics?:(:(

Typically the Process Characteristic will be noted in the Failure Cause column. If you have a Failure Mode that is a "process characteristic" there will also be a Failure Cause that will be a "process characterisitic" meaning both the Mode and the Cause would be listed in the Process Characteristic column of the Control Plan.

Typically the Process Characteristic will be noted in the Failure Cause column. If you have a Failure Mode that is a "process characteristic" there will also be a Failure Cause that will be a "process characterisitic" meaning both the Mode and the Cause would be listed in the Process Characteristic column of the Control Plan.

But if Your Failure Mode is Product in Characteristics , there is still a corresponding Process Characteristics in Potenfial failure cause?

The defective tamp cylinder was the Potential cause of failure as being called out in the PFMEA.. and the current control is Preventive Maintenance.

Where in PFMEa should i refer for the Process Characteristics?:(:(

Hello 6sigmaBBsphinx,

Do you have access to the AIAG APQP manual? If so, look at Section 6, beginning at page 31. Also, there are some (abbreviated) CP examples beginning at page 47. Not knowing how proficient you are in the development of CP's, that may be a good start. Please keep in mind that the DFMEA and the PFMEA are the input documents for the development of CP's.

Stijloor.

Heres another Example:

Process: Barcode Application

Product Char: No mis aligned Barcode

Process Characteristics: Defective Tamp cyliner

please comment

What is/are the process characteristic(s) that control the alignment of the bar code? That's what you want to cite as process characteristics. In your example, you're citing a failure of the process characteristic without defining what it is.

But if Your Failure Mode is Product in Characteristics , there is still a corresponding Process Characteristics in Potenfial failure cause?

From the PFMEA:

Operation: Applying bar code
Potential failure mode: Tamp cylinder goes haywire
Potential effect: Misaligned bar code
Potential cause: [Whatever might cause a tamp cylinder to go haywire]
Current Process Controls:
Prevention: [Doing whatever is necessary to prevent the potential cause, such as PM]
Detection: Inspection of bar codes for proper alignment

On the control plan:

Operation: Applying bar code (aligns with the PFMEA)
Product Characteristic: Proper bar code alignment
Process Characteristic: [Whatever might cause a tamp cylinder to go haywire] (aligns with the potential cause in the PFMEA)

From the PFMEA:

Operation: Applying bar code
Potential failure mode: Tamp cylinder goes haywire
Potential effect: Misaligned bar code
Potential cause: [Whatever might cause a tamp cylinder to go haywire]
Current Process Controls:
Prevention: [Doing whatever is necessary to prevent the potential cause, such as PM]
Detection: Inspection of bar codes for proper alignment

On the control plan:

Operation: Applying bar code (aligns with the PFMEA)
Product Characteristic: Proper bar code alignment
Process Characteristic: [Whatever might cause a tamp cylinder to go haywire] (aligns with the potential cause in the PFMEA)

Great example. You're more patient than I am....;)

From the PFMEA:

Operation: Applying bar code
Potential failure mode: Tamp cylinder goes haywire
Potential effect: Misaligned bar code
Potential cause: [Whatever might cause a tamp cylinder to go haywire]
Current Process Controls:
Prevention: [Doing whatever is necessary to prevent the potential cause, such as PM]
Detection: Inspection of bar codes for proper alignment

On the control plan:

Operation: Applying bar code (aligns with the PFMEA)
Product Characteristic: Proper bar code alignment
Process Characteristic: [Whatever might cause a tamp cylinder to go haywire] (aligns with the potential cause in the PFMEA)


Hers the scenario: from our PFMEA:

Potential Failure Mode: Bent Filter
Potential Effect: Deprime/Starvation
Potential Cause: Mis aligned Filter during Picking of Robot

What would be put on the Product and Process Characteristics in the control plan?

:(:(

Hers the scenario: from our PFMEA:

Potential Failure Mode: Bent Filter
Potential Effect: Deprime/Starvation
Potential Cause: Mis aligned Filter during Picking of Robot

What would be put on the Product and Process Characteristics in the control plan?

:(:(

Product Characteristic = Bent filter
Process Characteristic = Mis aligned Filter during Picking of Robot (Note: This sounds like a "symptom" to me. You could/should probably have a cause defined a little closer to the root cause. Why does the robot misalign the filter?)

Hers the scenario: from our PFMEA:

Potential Failure Mode: Bent Filter
Potential Effect: Deprime/Starvation
Potential Cause: Mis aligned Filter during Picking of Robot

What would be put on the Product and Process Characteristics in the control plan?

:(:(

Product Characteristic = Bent filter
Process Characteristic = Mis aligned Filter during Picking of Robot (Note: This sounds like a "symptom" to me. You could/should probably have a cause defined a little closer to the root cause. Why does the robot misalign the filter?)

This is exactly why I always suggest using process failures, rather than part defects, as the PFMEA failure modes. Consider:

Failure mode: Misaligned filter during picking by robot
Potential effect: Bent filter; deprime, starvation
Potential cause: ???

In the PFMEA stage you're forced to consider how to prevent potential process failures, which is much more likely to result in effective prevention controls. Now, in the control plan, the product characteristic is "Bent filter" and the process characteristic is whatever the potential cause(s) was/were determined to be in the PFMEA process.