Re: MIL-STD 105E

["W. J. Latzko" <Latzko@Worldnet.att.net>]

At 09:57 AM 8/1/2000 -0400, John Carradice wrote:
>  I have been unable to understand the order of the charts and they always 
> seem to confuse me.  To keep this short, I was wondering if the Den could 
> point me in a direction that I could acquire information regarding the 
> MIL-STD 105E, and more importantly how to read it.

Dear John,

MIL-STD-105E is a sampling plan that favors the producer and was used 
during World War II to get producers in line. Unless you are dealing with 
destructive testing, I think that the plan is pretty useless. Conceptually, 
Table I (p. 13) is used to select a plan. Unless there is cause to use 
something else, one uses General Inspection Level II. Look at the lot or 
batch size and select the appropriate amount. Find the letter under level 
II that is recommended. Go to that letter (A starts on p. 34)  Each letter 
has a set of OC (Operating Characteristic) Curves associate for different 
levels of AQL (Acceptable Quality Level). The table below the OC Curve 
table gives the plans for single, double and multiple inspections. Not all 
AQL levels can be used for some plans. The sample size is indicated as are 
the Accept/Reject numbers.

You would think that this makes it a nice plan. Until you realize that the 
AQL is protection for the producer, not the consumer. Besides this little 
fact, if your material is not destroyed in sampling, it is more economical 
to use the all or nothing plan. Acceptance Sampling plans are based on 
minimizing the cost of SAMPLING, not the total cost in use. For more on 
this, see chapter 15 in OUT OF THE CRISIS and read my paper referenced on 
page 432 of that book.

Have fun.

Bill Latzko
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