Operation of possible rework in control plan

[Skyrocketing]

Hello everyone,

One situation i had on recent IATF audit, worker was screwing the bolt with torque wrench and it hitted alarm on system when he started with operation and in front of auditors he repeated tightening - rework, and we got immediatly major NC because is not prescribed in control plan...
Since for rework you need to have customer approval (in this case risk is minor because it tights bolt with 3 Nm and final customer tight again up to 12 Nm) how i can adress this properly in control plan?
Thank you

 

[Jim Wynne]

Welcome to the Cove. Please explain more about the operation:

1. Was this a rework operation?
2. What triggered the alarm, and why?
3. Why did he keep going after the alarm sounded?
4. Is this rework a part of normal operations?

 

[Skyrocketing]

1. Auditors qualified this as rework, repeatble tightening operation, it could possible damage first steps of the thread
2.Alarm could be triggered if there is a increased dirt in thread (this product is not washed, straightly after machining it goes on assembly), if worker adjusted a little bit under angle a bolt vs thread etc
3. No, operation stopped, hydraulic screwdriver stopped, that he just reset the panel and screwed bolt again
4. Lets say, every 20-30 screwings happens..

Thank you Mr.Wayne!

 

[Sidney Vianna]

Since for rework you need to have customer approval

That’s not correct. IATF Definitions - Reworked product (8.7.1.4) vs Repaired product (8.7.1.5)

 

[Skyrocketing]

So this our operation is rework and we need just to have described it in tehnological instruction and contril method written in control plan?
Thank you

 

[Jim Wynne]

1. Auditors qualified this as rework, repeatble tightening operation, it could possible damage first steps of the thread
2.Alarm could be triggered if there is a increased dirt in thread (this product is not washed, straightly after machining it goes on assembly), if worker adjusted a little bit under angle a bolt vs thread etc
3. No, operation stopped, hydraulic screwdriver stopped, that he just reset the panel and screwed bolt again
4. Lets say, every 20-30 screwings happens..

Thank you Mr.Wayne!

So what you're saying if I understand you correctly, is that this action is a normal part of the process. If that's the case, it seems that the auditor is way off base and you should contest the finding.
Added in Edit: If this is a normal part of the process, it should be added to the control plan. If it's not there, there could be a minor NC involved, but certainly not a major.

 

[Skyrocketing]

Thank you Mr.Wayne!

 

[Matt's Quality Handle]

Added in Edit: If this is a normal part of the process, it should be added to the control plan. If it's not there, there could be a minor NC involved, but certainly not a major.

It sounds like a "normal" part of the process that just hasn't been documented yet. Document it, add it to your Control Plan/Work Instructions. Depending on how your documents are structured, you might be able to describe it in your work instructions, then have your CP reference the WI.

This caused us heartburn during the IATF 2016 transition. We were doing a metal stamping/forming operation, and there was frequently "rework" that was part of the process. Mainly around hammering or filing of burrs. We wrote a general rework work instruction, and listed it in the control plan. Our control plan was used as the basis for our work instructions, so the CP was not on the floor.

If the auditor questioned it, we could point to the CP, which was approved by the customer at PPAP.

 

[Sebastian]

In my opinion it wasn't rework.
Rework is post product inspection activity.

Tightening torque is process characteristic, not product.
Alarm was triggered not by failure to achieve torque target value, but minimal number of turns.
So number of turns is additional process characteristic here.

I would expect to find both these characteristics in PFMEA and control plan.
Detection control is torque wrench angle sensor.
Detection effectiveness depends on operators reaction to alarm.
In control plan I would expect in reaction plan column description of activities performed by operator, these which de has done in front of auditor or reference to instruction including guidelines for operator how to behave when alarm goes on.
It might be unscrewing, visual check of thread condition, using air gun to remove dirt and tightening bolt again.

There was no post process inspection, so product can't be found detective and there is no reason for implementing correction.
Rework is method of correction implemented over defective product.
So on auditor's place I would review PFMEA, control plan and work instruction carefully, to find justification for what I have seen.
If not, reaction plan is better

Some may say, that tightening torque could be checked with a calibrated torque wrench, so it has to be treated as product characteristic, but in my opinion it is not proper method to control this characteristic.