Thanks for your comments, Guy
I received a few responses off line and it sounds like there exists no
commonly collected and shared data base and that it is every company for itself on
this matter.
As one colleague responded, "the question is an 800 pound gorilla in the
room" that is being ignored (perhaps in the hopes that it is a mirage?) I
suspect that no one wants to admit that their products are anything short of
perfect. Who would?
Your opening clarification question was a good one but I was thinking only
of initial turn on as I figured that was the easiest to collect and store.
BTW, I think that the IPod may have been a bit of planned obsolesce. I have
a major brand name electric shaver with simple rechargeable AA batteries that
recently found were welded in place. They obviously (or at least apparently)
intended for it to be either pitched or returned for the repairs at a
handsome margin. Certainly can't trust the consumer to change AAs.
Joe
In a message dated 6/18/2007 10:28:11 AM Pacific Daylight Time,
[log in to unmask] writes:
Are you talking field return or OEM in factory initial turn on.
If you are talking in-factory initial turn-on, typical device, solder
Defects number 1. Mostly opens because shorts are easy to detect with
inspection and ICT. Though in my experience there special events on the
factory floor that can change all that.
If you are talking field returns, we have another story. And must include,
electronic design problems, mechanical design problems and customer abuse or
misuse.
I kept this kind of data at an Organ Company for years. The data set ran
from 1986 to 2000. We stored the information on a VAX 8300. I left in May of
2000. I doubt they continued to collect and analyze the data as that machine
was expensive to maintain and in a DataTrieve database, not easy to port
over to Windows.
I can tell you this. During that time there were periods when field failures
were primarily design related, others when failures were primarily board
fab. related, periods when failures were primarily component related
(sometimes semi-conductor other times passives) and other periods where
failures were primarily related to manufacturing problems. All of these
would be embarrassing for some interested party because they were
attributable to some special cause of failure and we were able to identify
that special cause.
There were very few periods in which the population of defects would not
have been influenced by one of these assignable causes. So, even this huge
data set would not tell you want the most common "common cause" defect would
be. My gut tells me it would be customer misuse followed by, in the case of
Allen Organ, electrical or mechanical design problem.
Other companies might have more design problems than misuse problems. BTW
these merge. You can have a design problem that customers attempt to fix,
which turns into a misuse problem . . . . Ever tried to change a battery in
an iPod? Is an unsuccessful attempt a design problem or customer misuse?
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad
Sent: Monday, June 18, 2007 10:59 AM
To: [log in to unmask]
Subject: [TN] Failure statistics breakdown data?
Good (time of day here) colleagues,
Does anyone know of a statistical base that identifies assembly failures
and traces them to causes with some sort of breakdown?
That is failures traced to assembly only (e.g., opens, shorts, insufficient
cleaning, etc.), failures related to PCB manufacturing only (e.g., PTH
failure, opens, shorts, CAF, etc.) and failures traced to the components
themselves of any cause (ESD, overheating, thermal cycling failure, etc.).
I realize that this may be a sensitive topic for some folks and am thus
open to taking any such data off line.
However any perspective based on experience and "guessimates" from the
general audience is encouraged and most welcomed to see if there is any kind
of consensus of experience and how close it matches with the the industry's
general perceptions.
Rough (in the same city at the ball park) estimates are OK.
Thanks in advance for any form of light that can be shed while I fumble
around in the dark feeling for the "main lightswitch". ;-)
Best to all,
Joe
************************************** See what's free at http://www.aol.com.
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