# How to see sampling size chart at Level S2, AQL=0.65%

Discussion in 'Sampling, Standards and Inspection' started by JennSia, Jan 16, 2020.

1. ### JennSiaNew Member

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Hi all, we have a customer request to fill in the sample size for the visual inspection for lot size 5000 and 11000, the sampling standard we are using is ANSI/ASQ Z1.4, AQL=0.65%, Level S2, and we have feedback to customer that the sample size is 20, however customer feedback that it should be 8 instead of 20. Need some advice please.

2. ### Andy NicholsModeratorStaff Member

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Sometimes customers don't always understand. Could you provide them with the sample they require, while -at the same time - actually using the bigger sample (to give you greater confidence)?

3. ### JennSiaNew Member

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We explained to them thru email on the method to take sampling size, we also sent the work instruction to them, however they said we use the chart in wrong way, so I am wondering for lot size 5k and 11k, is the sample size is 20 under level s2, AQL=0.65%?

4. ### Andy NicholsModeratorStaff Member

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Are you contractually obligated to this sampling scheme?

5. ### _Zeno_Member

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This might provide some insight, particularly the section "Fixed Sample Size Tends toward Constant Quality Protection". It's much easier to implement a fixed sample size and isn't subject to being gamed by playing with lot sizes.

Construct a AOQL level graph of the plan you'd like to propose (ie: n=35, c=0 plan has a max AOQL level of 1%). The maximum AOQL level is the worst case risk to your customer. As long as it doesn't exceed your customers expectations, you should be able to substitute it for the Z1.4 plan.

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• ###### OC Curves (Grant & Leavenworth, Statistical Quality Control, 5th edition).pdf
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Last edited: Jan 16, 2020
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