From: Stan Hilliard shilliard@samplingplans.com
Date: 16 Jul 2001
Time: 23:49:35
Hi Sergio,
>> Greatly increasing the sample size during the last inspection to satisfy the changed AQL doesn't seem valuable. Is there any way around this?
You can get around this with a two-point sampling plan based on a constant operating characteristic curve. You specify the producer's point (AQL, producer's risk) and the consumer's point (RQL, consumer's risk). These two points determine the constant oc curve. With this, you can develop a fixed-n sampling plan (constant n & Ac). The method is described starting here:
www.samplingplans.com/usingoccurves.htm
All of the calculations are done with software program TP105:
www.samplingplans.com/software_oc.htm
You might still have to increase or decrease the sampling rate near the end of the run to get the fixed-n, but to a much smaller extent.
Additionally, having constant oc-curve provides the same protection for all lots. This seems reasonable compared to your current plan, which provides different levels of protection for different lots.
Stan Hilliard