Do CTQs need to be equipment specific?

[buralbe]

Good morning to everyone,

We have established process CTQs since few years now in my company but I was wondering if they need to be equipment specific or not.
For example, we have two reflow ovens where we introduced a CTQ to monitor the max temperature. The limits, the measurement tooling and the equiment are exactly the same for both reflow ovens. I created two different CTQs, but do I need to use two different CTQs? Or the CTQ is only one (max temp) and I can use it for all the ovens? There would be of course a different data collection for every equipment, but the CTQ would be one.

I hope my question makes sense.

Thanks!

 

[John C. Abnet]

Good day @buralbe ;
I know CTQ as "Critical To Quality".

What does CTQ stand for in your post?

 

[buralbe]

Hi John,

I am sorry it wasn't clear. I mean Critical to Quality.

Thanks

 

[Jim Wynne]

Hi John,

I am sorry it wasn't clear. I mean Critical to Quality.

Thanks

What industry? What certification is involved (ISO 9001, e.g.) How does your company define "Critical to Quality"?

 

[John C. Abnet]

Good day @buralbe ;
I'm not sure what governance you are under (I assume IATF 16949 and/or your organization's own internal requirements).

IATF, for example, does not specify. Therefore, unless your organization's internal requirements specify, then it is up to you/your organization.
Be selfish. Do what is BEST and NEEDED by your organization.

It sounds to me as if the "CTQ" you are referring to are actually process controls.

Remember, however, that it sounds as if you'll be setting precedence. I would council that you determine and consider what I refer to as "control resolution" . For example, if the process controls for the type of equipment you are referring to are ALWAYS the same for that type of equipment, then to establish common/single process control by this equipment type is likely acceptable. HOWEVER, if the controls for this type of equipment may change based on the product/part numbers being produced, then the control resolution should be maintained and the PRODUCT/part number level. If that is the case (I assume it is) then I reiterate, that I would recommend establishing controls for each PRODUCT/part number.

Hope this helps.
Be well.

 

[buralbe]

John, Jim,

Thanks for your answers.

I work for an Electronic Contract Manufacturer. We have several customers with different level of specifications and expectations. The most demanding customers in term of Quality use Automotive standards even if they are not Automotive.

 

[Jim Wynne]

John, Jim,

Thanks for your answers.

I work for an Electronic Contract Manufacturer. We have several customers with different level of specifications and expectations. The most demanding customers in term of Quality use Automotive standards even if they are not Automotive.

Once again, What certification is involved (ISO 9001, e.g.)? How does your company define "Critical to Quality"?

 

[Miner]

There is a lot of confusion over the usage of CTQ and not all agree. Most blur the distinction and meaning of CTQ. Your usage does this. The following is the one that I teach and feel is least confusing.

• CTQ - The product characteristics that are critical to ensuring that the customer's needs are met
• KPOV (Key Process Output Variable) - the associated measurable process output
• KPIV (Key Process Input Variable) - the process parameters (e.g., temperature, etc.) that must be controlled in order to consistently provide a KPOV with minimal variation

This graphic illustrates this relationship.

 

[John C. Abnet]

I echo what @Miner points out in regards to "CTQ".

In addition, specific to an organization's internal controlled processes and documentation, I would add the following....

"If it is WRONG or GONE, can it lead to a nonconformance?"

This is an easy and memorable way to vet what is and is not critical to quality/in need of control.

For example, ....
* Sign"X" says... "turn off lights when leaving the room".: Sign "X" likely does not meet the condition for CTQ
HOWEVER,...
* Sign "Y" says ... "push this button or all parts will be N/G".: Sign "Y" does meet the condition for CTQ and control should be considered.

Hope this helps.
Be well.