From: Salley Kamb
Date: 04 May 2000
Time: 11:32:04
I am trying to develop a variables sampling plan for incoming lots of printed wire circuit boards. We currently measure height,width and thickness and pass the lots (size 1500-15,000)on an attribute sampling plan (AQL 1.0). It is the feeling that it would be worth putting a variables sampling plan into place to reduce sample size, and gather more information. We would like a program, easy to use by all levels of employees, that allows for entering the data and performs all calculations and table look ups automatically. Does this exist? Also, we are not sure variables sampling is the way we need to go. Would control charts and histograms (possible with subgroups constructed from samples taken from specific places on the boards) provide us with useful accpetance information about the quality of our suppliers process and the lot? For example, from past data, we have performed ANOVA to determine that our suppliers process is capable, but not centered and we get lots that have relativelt the same Std dev, but different means.