finding the correct AQL

[Former Member]

Hi,

   I know in the sampling scheme we define the sample sizes for various inspection severities and AQLs. But how does the system know which AQL to pick for a given lot size ? Also how does it know which inspection severity to pick ? I am guessing that if DMR is NOT set up then the severity is always normal but if DMR is set up then the severity could be reduced or tightened.

Thanks

[former_member1000434]

Hi,

Can I add onto this question.

I have created my sample scheme and attached it to my sampling procedure so I can then attach that to the DMR.

the issue I am having is I want a DMR with 6 steps with different sample size every time it reduces in the DMR.

For instance if I get 55 pieces consistently in my lot: (assuming all inspection pass)

the first 5 lots are checked with a sample size of 8, (normal)

then the next 5 lots are check with a sample size of 7, (reduce)

then the next 5 lots are checked with a sample size of 5, (reduce)

then the next 5 lots are cheeked with a sample size of 4, (reduce)

then it moves into a skip stage for 5 lots (skip)

if any lot fails then the inspection will tighten to a sample size of 13 (tighten)

I cannot get more than one reduce value even though it is in the sample scheme.

[Martin_H]

  I am guessing that if DMR is NOT set up then the severity is always normal but if DMR is set up then the severity could be reduced or tightened.
Thanks

This guess is not correct. You specify the severity in the sampling procedure, and if you want to have always reduced inspection then just set this in the procedure.

Regards

MH

[Former Member]

I know that as well. In my attached screenprint I have a scheme attached to a procedure. The scheme however has multiple AQL/Severity combinations. How does the system know which one to pick ?

Thanks

GS

[Martin_H]

I do not see any screenprint you have attached. However, try the following:

• TAC QDV3 and open your sampling procedure
• Check that sampling type is "use sampling scheme"
• Click on the continue button
• Click on the "additional data" button

--> it should open a dialog window "reference to sampling scheme" and telling you the inspection severity and the AQL value chosen for this sampling procedure.

Regards

MH

[Former Member]

how does the system know which AQL to pick for a given lot size ?

>>Its from Sampling procedure.You define the AQL in SP.

Also how does it know which inspection severity to pick ?>> Its from DMR

[former_member218067]

AQL Value- Acceptable quality level (AQL)

The maximum share of nonconforming units in percent or maximum number of
defects in every 100 units that represent the upper limit for satisfactory
quality in an acceptance sampling inspection. please refer to AQL sampling systems ISO 2859-1 and ISO 3951 for further information

DD

[Former Member]

excuse me....but I know the defination of AQL. I want to know how the system picks the correct AQL. If you look at the sampling procedure and the associated sampling scheme, there could be multiple AQL/severities which define the sample sizes. How does the system know which one to pick.

[Martin_H]

YOU define which AQL the system picks by setting this value in the sampling procedure (you have to specify sampling scheme, inspection severity, AQL value). If you then specify this procedure in your inspection plan, the system takes it when creating inspection lots.

What of this is unclear to you?

Regards

MH