Product annual review
Dear all,
I was doing my annual product review to review the specification either it meets our internal specification or not. I calculated lower control limit and upper control limit given the formulation as (average - 2 x STD deviation) LCL and (average + 2 x STD Deviation ) UCL. I have never found that the LCL and UCL is over the specification limit. But this year i'm having difficulty as my UCL is over my specification limit. May I know what should i do next?
Thanks.
Hi Quality X,
This means that the standard deviation had been increased ,something went wrong in the inputs or process that increase the deviations and variability which lead to more STD value ,you should look for the reason and start to restore your basic condition and reduce the variation , this needs you to go to the line and start with your team investigate the reason of deviation.
Just note : normally UCl /LCL are 3+STD ,I understand that you need more narrow limits , you can also use Cpk to review process capability.
BR,
Ehab
Your results indicate something has changed within your process, causing the increase in your SD value
Has something new been introduced to your process?, Equipment, new raw material, New staff, change in process parameters etc, you will need to identify the cause before you can start to get the process back in control.
Perhaps the first step is to look closely at your data to see if you can identify when any change occurred - when did the SD start to shift?
Dear all,
I was doing my annual product review to review the specification either it meets our internal specification or not. I calculated lower control limit and upper control limit given the formulation as (average - 2 x STD deviation) LCL and (average + 2 x STD Deviation ) UCL. I have never found that the LCL and UCL is over the specification limit. But this year i'm having difficulty as my UCL is over my specification limit. May I know what should i do next?
Thanks.
Hi Quality x,
Some actual data might generate more specific comments.