Receiving Inspection AQL - Am I allowed to just pick a AQL?

#1
Hello,

I'm very new to this thread so I hope I'm in the right place....I have a question about receiving inspection AQL's. I'm ISO 9001:2015 certified and I have product coming in from an outside vendor and I would like to use MIL-STD-105E Table II-A the Single Sampling Plans for Normal Inspection (Master Table). The supplier I'm using provided Final Inspection IP's and Control Plans and sent me a sample part that I measured on my CMM and all of my measurements are within a .0001". With this in mind I would like to check each lot regardless of size (lots range from 10 pcs to 100 pcs) at a 6.5 AQL. My question is am I allowed to just pick a AQL? I feel like this has to be explained somewhere I'm not sure where.....

Thanks!
 

ScottK

Not out of the crisis
Staff member
Super Moderator
#2
Hello,

I'm very new to this thread so I hope I'm in the right place....I have a question about receiving inspection AQL's. I'm ISO 9001:2015 certified and I have product coming in from an outside vendor and I would like to use MIL-STD-105E Table II-A the Single Sampling Plans for Normal Inspection (Master Table). The supplier I'm using provided Final Inspection IP's and Control Plans and sent me a sample part that I measured on my CMM and all of my measurements are within a .0001". With this in mind I would like to check each lot regardless of size (lots range from 10 pcs to 100 pcs) at a 6.5 AQL. My question is am I allowed to just pick a AQL? I feel like this has to be explained somewhere I'm not sure where.....

Thanks!
Welcome to the Cover venom21.

The AQL in this plan really tells you how many defectives you can have in your sample and still accept the lot.
So the first question is: can you accept defectives? If you cannot then I would suggest you ditch this plan and look at Zero Acceptance Number Sampling Plans - Like Squeglia's.
I'm seeing more and more companies go to this.

If you are just using MIL-STD-105E (which is obsolete, BTW. ANSI/ASQ Z1.4 is the replacement. Pretty much the same though) to determine a sample size then AQL really doesn't matter. What matters is the inspection level.
 

Statistical Steven

Statistician
Staff member
Super Moderator
#3
If your lot size is between 10 and 100, then sampling plans like Z1.4 might be inappropriate. For an AQL of 6.5, the standard requires a sample size of 3 and acc/rej of 0. Such plans though have a low AQL, have a VERY high RQL (greater than 50%). If the testing you are doing is no destructive, you might as well 100% inspection versus a sampling plan.

To answer you more generic question, unless specified by contract, you select the AQL based on the risk you are willing to accept.


Hello,

I'm very new to this thread so I hope I'm in the right place....I have a question about receiving inspection AQL's. I'm ISO 9001:2015 certified and I have product coming in from an outside vendor and I would like to use MIL-STD-105E Table II-A the Single Sampling Plans for Normal Inspection (Master Table). The supplier I'm using provided Final Inspection IP's and Control Plans and sent me a sample part that I measured on my CMM and all of my measurements are within a .0001". With this in mind I would like to check each lot regardless of size (lots range from 10 pcs to 100 pcs) at a 6.5 AQL. My question is am I allowed to just pick a AQL? I feel like this has to be explained somewhere I'm not sure where.....

Thanks!
 
#4
ScottK,

Thank you for the quick response, also I understand that the standard is obsolete but I was under the impression it could still be referenced so thank you for the heads up.

As for your your next question, yes and no if a no, if a critical feature is like a .0001" out of tolerance we can accept but if it's a something critical I would reject and inspect the entire lot.

As for the Zero Acceptance Number Sampling Plans I just started to look at Squeglia's and it looks like it could also work, do you have a link or something that explains how to determine which AQL level to use?

Thanks again
 
#6
Eredhel,

Not exactly, my understanding of the standard is that I have to make sure that my vendor can supply quality product consistently and that product needs to be verified either by the vendor or by me, which the vendor does. I just want to perform an additional check on the product when its received.

My question is how do I determine the best AQL to inspect parts to? And if i'm not understanding ISO 9001:2015 please let me know.
 

ScottK

Not out of the crisis
Staff member
Super Moderator
#7
ScottK,

Thank you for the quick response, also I understand that the standard is obsolete but I was under the impression it could still be referenced so thank you for the heads up.

As for your your next question, yes and no if a no, if a critical feature is like a .0001" out of tolerance we can accept but if it's a something critical I would reject and inspect the entire lot.

As for the Zero Acceptance Number Sampling Plans I just started to look at Squeglia's and it looks like it could also work, do you have a link or something that explains how to determine which AQL level to use?

Thanks again
The AQL is generally based on the level of risk you can tolerate and agreement with the supplier that they can be held to that AQL. An AQL of 6.5 is generally pretty loose where I've worked but that's been in drug and device. An AQL of 1.0 or 1.5 is more typical for most characteristics.

Here's an older thread on determining AQL level:

AQL (Acceptable Quality Level) vs. PPM (Parts per Million) - Equivalences?
 

Eredhel

QA Manager
Trusted
#9
You're on the right track, I just wanted to make sure you didn't think there was some sample size specific ISO 9001 requirement because there isn't. Like Scott said it's up to you all to balance the risk and pick something reasonable.
 

AndyN

A problem shared...
Staff member
Super Moderator
#10
Hello,

I'm very new to this thread so I hope I'm in the right place....I have a question about receiving inspection AQL's. I'm ISO 9001:2015 certified and I have product coming in from an outside vendor and I would like to use MIL-STD-105E Table II-A the Single Sampling Plans for Normal Inspection (Master Table). The supplier I'm using provided Final Inspection IP's and Control Plans and sent me a sample part that I measured on my CMM and all of my measurements are within a .0001". With this in mind I would like to check each lot regardless of size (lots range from 10 pcs to 100 pcs) at a 6.5 AQL. My question is am I allowed to just pick a AQL? I feel like this has to be explained somewhere I'm not sure where.....

Thanks!
I've been heavily involved in this decision (or at least, the aftermath of the decision being made). Firstly, since your supplier provides their inspection data etc. can I ask WHY you feel it's necessary to sample?
 

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