Re: Variation in Small Batches

[Paul Hollingworth <Paul@4gm.com>]

Douglas Bedell <dhbedell@mindspring.com> writes
>I feel he should be measuring
>*something,* perhaps at least their record in meeting promised customer
>delivery dates. 

On time order fulfilment is a key quality characteristic and needs to be
monitored, for sure. But it is an output (effect) measure not a process
(cause) measure. What will you do with the answer?

>But is there an SPC application for small batches at a
>"country machine shop"? What's the pertinence of variation here?

The parts may change, the batch sizes may vary, but the processes used
will be similar every time. Understanding of the variation in these
processes and the systems of which they are part is essential.

Don Wheeler has written an excellent little 'how to' book called "Short
Run SPC". I advise you start by reading this.

PH


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Paul Hollingworth                       4GM Consulting  
email: PH@4GM.com                       http://www.4GM.com
phone: +44(0) 1423 322225               fax: +44(0) 1423 322205 
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