IATF16949 audit requirement - Auditor request UCL and LCL must be show Xbar-R,

[binhdc]

Hi everyone, last time our company had IATF audit, auditor request UCL and LCL must be show Xbar-R, but at current month not complete so we can not calculate UCL and LCL of this month and update on Xbar-R sheet then he suggest use data last month get UCL & LCL then draw on next month sheet. is this right? How about your site control this. This thing there no regulation for require it.

Thankyou

 

[Howard Atkins]

If you do not have a UCL and LCL then how do you know if you are out of control.
What is the point of setting the control limits after the event.
You are supposed to be controling in real time, not a month later.

It sounds like you should have had a non conformity for
Failure to understand statistical concepts

9.1.1.3 Application of statistical concepts
Statistical concepts, such as variation, control (stability), process capability, and the consequences of over-adjustment, shall be understood and used by employees involved in the collection, analysis, and management of statistical data.

 

[binhdc]

If you do not have a UCL and LCL then how do you know if you are out of control.
What is the point of setting the control limits after the event.
You are supposed to be controling in real time, not a month later.

It sounds like you should have had a non conformity for
Failure to understand statistical concepts

9.1.1.3 Application of statistical concepts
Statistical concepts, such as variation, control (stability), process capability, and the consequences of over-adjustment, shall be understood and used by employees involved in the collection, analysis, and management of statistical data.

Thankyou
You are correct, we had a non conformity for that issue, So how to get UCL and LCL for current month? data is not enough.. So can we use data previous month and calculate UCL, LCL and apply for current month? is this correct?

 

[Howard Atkins]

What are your corrective actions for the NC?
I would have thought training was needed, the trainer should give you the answer based on your specific problem and allow you to understand in the future.
You are asking for a correction but you need to understand fully SPC which gives many choices
Sorry if you want a quick fix but that will not help you in the future

 

[binhdc]

What are your corrective actions for the NC?
I would have thought training was needed, the trainer should give you the answer based on your specific problem and allow you to understand in the future.
You are asking for a correction but you need to understand fully SPC which gives many choices
Sorry if you want a quick fix but that will not help you in the future

Thankyou
The trainer request use data previous and get UCL, LCL set-up for next.. but i wonder this not correct the method, so i would like to know how about other action.
Anyway, i will study SPC more to understand it.
Thankyou~

 

[AMIT BALLAL]

Hi everyone, last time our company had IATF audit, auditor request UCL and LCL must be show Xbar-R, but at current month not complete so we can not calculate UCL and LCL of this month and update on Xbar-R sheet then he suggest use data last month get UCL & LCL then draw on next month sheet. is this right? How about your site control this. This thing there no regulation for require it.

Thankyou

Of course, you'll need some data to calculate control limits. Data of 20 subgroups / 1 month's data can be used to calculate these. These can be considered as trial control limits in the study for next several months for finding special causes. If the process is not showing special causes, you can recalculate control limits based on available data.

I would recommend the following article:
When to Calculate, Lock, and Recalculate Control Limits.

 

[Jim Wynne]

Hi everyone, last time our company had IATF audit, auditor request UCL and LCL must be show Xbar-R, but at current month not complete so we can not calculate UCL and LCL of this month and update on Xbar-R sheet then he suggest use data last month get UCL & LCL then draw on next month sheet. is this right? How about your site control this. This thing there no regulation for require it.

Thankyou

Why are you calculating control limits on a monthly basis? What is the process being charted?

 

[joekirk]

Jim has a valid question. You should be monitoring your data and recalculating your control limits as needed (if you have a shift in your process (good or bad)).