My experience: without some form of QPL (either an external one or
preferably one you make yourself) you are the mercy of the component buyers.
I remember when the buyers decided they could save money by buying a
different brand of resistor (spiral band around the body) in stead of the
composite body resistor we were using (old Allen Bradleys). Sure enough, the
inductance in the new resistors caused some circuits to fail. 
Some generic components are not generic enough!

It's always the little things that bite you in the rear.
Ahne.


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Genny Gibbard
Sent: Monday, 22 October, 2007 10:41
To: [log in to unmask]
Subject: Re: [TN] Second sources - generic components

Reasonable suggestion, in many ways.
However, I've spent some time looking into what a QPL is (we don't build
military equipment, so I was unfamiliar with the term).
Unfortunately, after reviewing what is involved in achieving QPL status, I
think if we went only with QPL components, a 10K 0402 chip resistor would no
longer cost only $0.002.  
I think I need to determine an acceptable compromise between QPL approval
process and my own gut feeling on whether a part is a good cross.  I have to
figure out how to document my gut feeling so my evaluation process is
repeatable for others.

Maybe I should have chosen different terminology.  I think I'm opening this
up for a Dewey free-for-all...  :)

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]
Sent: October 19, 2007 11:45 AM
To: [log in to unmask]
Subject: Re: [TN] Second sources - generic components

Hi
Why not consider adopting the Military QPL's.  Presumably your work would be
largely done.
Monitoring would be your continued responsibility.
Bernie Kessler





At 10:33 AM 10/19/2007:
>Has anyone defined any internal standards for how to approve second 
>sources for "generic" components by datasheet review alone, without 
>running exhaustive tests on every source?
>I just don't see the point in running 3 weeks of environmental and 
>stress tests in order to qualify a $0.002 10Kohm chip resistor second 
>source.  I should be able to look at a datasheet and say "yes this is 
>OK".  But when you make OEM products you need to justify why you are 
>approving it with this method, and I would like to write up some sort
of
>standard to cover off the bases.
>
>I'm looking for places to start.  Thoughts?
>
>Thanks as always, and regards,
>Genny.
>

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