Manufacturing - Tracking

I work for a small manufacturer. We ship a product with several different
PCB assemblies. We've never had a good system to track exactly what goes
out the door to each customer. I am in the process of rectifying this and
wanted to see what others do. At a minimum I want to relate the PCB
revision and PCB assembly revision as well as the firmware revision back to
a serial number. I'd like to get even more detailed, but I am not sure at
what point it is too much data/work. I thought of tracking the lot that the
assembly came from and perhaps even trace this back to the reel of a
particular component. It would be nice to say "we have a problem with
component x from lot y... how many boards are affected?". At this point I
can see it becoming quite complex because we never use an entire reel of
one particular component on a given lot of PCB assemblies. For example, a
capacitor from a single reel might be used in several different PCB
assembly lots (POs). Moreover, since we only assemble the final product
here and our PCB assemblies are provided turnkey this means we would have
to rely on our contract manufacturer to provide this data.

So, I was just curious how other manufacturers tracked their products and
if anyone got to that level of detail.	   
					
---------------------------------------		
Posted through http://www.EmbeddedRelated.com

On 02/17/2011 08:46 PM, eeboy wrote:
> I work for a small manufacturer. We ship a product with several different
> PCB assemblies. We've never had a good system to track exactly what goes
> out the door to each customer. I am in the process of rectifying this and
> wanted to see what others do. At a minimum I want to relate the PCB
> revision and PCB assembly revision as well as the firmware revision back to
> a serial number. I'd like to get even more detailed, but I am not sure at
> what point it is too much data/work. I thought of tracking the lot that the
> assembly came from and perhaps even trace this back to the reel of a
> particular component. It would be nice to say "we have a problem with
> component x from lot y... how many boards are affected?". At this point I
> can see it becoming quite complex because we never use an entire reel of
> one particular component on a given lot of PCB assemblies. For example, a
> capacitor from a single reel might be used in several different PCB
> assembly lots (POs). Moreover, since we only assemble the final product
> here and our PCB assemblies are provided turnkey this means we would have
> to rely on our contract manufacturer to provide this data.
>
> So, I was just curious how other manufacturers tracked their products and
> if anyone got to that level of detail.	

Why are you tracking?  That'll tell you a lot about what you want to track.

Aerospace/defense sort of suppliers do everything by revision level: if 
you bump the rev of a lower-level part, then you have to bump the rev of 
the assembly.  Then all you have to know is that thus-and-so serial 
number was at rev level such-and-such, and you know the rev levels of 
all the parts.

That can get onerous, but at least you _know_, and if necessary you can 
duplicate a system.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

>Why are you tracking?  That'll tell you a lot about what you want to
track.

Part of the tracking is so that when they call up with a technical question
we already have a background on what PCB assemblies and what rev firmware
is in the widget.

However, it would be nice to track to the component level. For instance, we
recently had a board where a particular capacitor failed. If I could know
what lot of PCB assemblies these were coming from or what lot of components
they came from I could quickly isolate the problem. For instance if all the
bad caps were spread across several assembly lots but were all from the
same reel (one reel of this component spanned these assembly lots) I could
start to draw some conclusions about why the part is failing. Perhaps I am
trying to do too much. I would *hope* I don't have to trace failures that
often.

	   
					
---------------------------------------		
Posted through http://www.EmbeddedRelated.com

"eeboy" <jason@n_o_s_p_a_m.jasonorsborn.com> writes:

> I work for a small manufacturer. We ship a product with several different
> PCB assemblies. We've never had a good system to track exactly what goes
> out the door to each customer. I am in the process of rectifying this and
> wanted to see what others do. At a minimum I want to relate the PCB
> revision and PCB assembly revision as well as the firmware revision back to
> a serial number.
> I'd like to get even more detailed, but I am not sure at
> what point it is too much data/work. I thought of tracking the lot that the
> assembly came from

The above is what we do. The bare PCB is treated as another component,
so if it changes significantly it's revision level is automatically
incorporated in that of the assembly, Each serial number is linked to
the lot number, and the lot is defined by a list of assembly part
numbers and revision levels.

> and perhaps even trace this back to the reel of a
> particular component. It would be nice to say "we have a problem with
> component x from lot y... how many boards are affected?". At this point I
> can see it becoming quite complex because we never use an entire reel of
> one particular component on a given lot of PCB assemblies. For example, a
> capacitor from a single reel might be used in several different PCB
> assembly lots (POs). Moreover, since we only assemble the final product
> here and our PCB assemblies are provided turnkey this means we would have
> to rely on our contract manufacturer to provide this data.

For general manufacturing I think this is too expensive to do for just
the reasons you give.


> So, I was just curious how other manufacturers tracked their products and
> if anyone got to that level of detail.	   

We do incorporate a "job number" in purchase orders, so in principle we
can establish the boards at risk. I.e., all those made after the arrival
of the PO that contain the part. I can't see a practical way to do
anything more. A reel can last a long time. Assemblers lose a few parts
here and there, or open the new reel instead of the old one.


-- 

John Devereux

"eeboy" <jason@n_o_s_p_a_m.jasonorsborn.com> wrote in message 
news:_J-dnbmlY6e3isPQnZ2dnUVZ_v-dnZ2d@giganews.com...
> >Why are you tracking?  That'll tell you a lot about what you want to
> track.
>
> Part of the tracking is so that when they call up with a technical 
> question
> we already have a background on what PCB assemblies and what rev firmware
> is in the widget.
>
> However, it would be nice to track to the component level. For instance, 
> we
> recently had a board where a particular capacitor failed. If I could know
> what lot of PCB assemblies these were coming from or what lot of 
> components
> they came from I could quickly isolate the problem. For instance if all 
> the
> bad caps were spread across several assembly lots but were all from the
> same reel (one reel of this component spanned these assembly lots) I could
> start to draw some conclusions about why the part is failing. Perhaps I am
> trying to do too much. I would *hope* I don't have to trace failures that
> often.
>
>
>
> --------------------------------------- 
> Posted through http://www.EmbeddedRelated.com


In my limited experience failures due to a particular part (where it is not 
a design issue) can be tracked by batch. IE a dud batch of caps / ICs etc 
are used in a production run. Keep a s/m range for each batch run. 

On Thu, 17 Feb 2011 22:46:14 -0600, eeboy wrote:

> I work for a small manufacturer. We ship a product with several
> different PCB assemblies. We've never had a good system to track exactly
> what goes out the door to each customer. I am in the process of
> rectifying this and wanted to see what others do. At a minimum I want to
> relate the PCB revision and PCB assembly revision as well as the
> firmware revision back to a serial number. I'd like to get even more
> detailed, but I am not sure at what point it is too much data/work. I
> thought of tracking the lot that the assembly came from and perhaps even
> trace this back to the reel of a particular component. It would be nice
> to say "we have a problem with component x from lot y... how many boards
> are affected?". At this point I can see it becoming quite complex
> because we never use an entire reel of one particular component on a
> given lot of PCB assemblies. For example, a capacitor from a single reel
> might be used in several different PCB assembly lots (POs). Moreover,
> since we only assemble the final product here and our PCB assemblies are
> provided turnkey this means we would have to rely on our contract
> manufacturer to provide this data.
> 
> So, I was just curious how other manufacturers tracked their products
> and if anyone got to that level of detail.
> 					
> --------------------------------------- Posted through
> http://www.EmbeddedRelated.com

Take a look at OpenERP.  Might do what you want.

http://www.openerp.com/




-- 
Joe Chisolm
Marble Falls, Tx.

eeboy wrote:
> I work for a small manufacturer. We ship a product with several different
> PCB assemblies. We've never had a good system to track exactly what goes
> out the door to each customer. I am in the process of rectifying this and
> wanted to see what others do. At a minimum I want to relate the PCB
> revision and PCB assembly revision as well as the firmware revision back to
> a serial number. I'd like to get even more detailed, but I am not sure at
> what point it is too much data/work. I thought of tracking the lot that the
> assembly came from and perhaps even trace this back to the reel of a
> particular component. It would be nice to say "we have a problem with
> component x from lot y... how many boards are affected?". At this point I
> can see it becoming quite complex because we never use an entire reel of
> one particular component on a given lot of PCB assemblies. For example, a
> capacitor from a single reel might be used in several different PCB
> assembly lots (POs). Moreover, since we only assemble the final product
> here and our PCB assemblies are provided turnkey this means we would have
> to rely on our contract manufacturer to provide this data.
> 
> So, I was just curious how other manufacturers tracked their products and
> if anyone got to that level of detail.	   
> 					
> ---------------------------------------		
> Posted through http://www.EmbeddedRelated.com

Whatever you do use a proper database system and not a spread sheet. I 
shudder when I hear someone complain they can only get 64K lines in 
Excel - that is at least 10x past where they should have done something 
else.

I once worked on a project where they had data on hundreds of parts in a 
spread sheet. The part had a serial number and the subassemblies had 
version and serial numbers. They were trying to correlate burn in test 
failures to see if there was some common factor by hand. I exported the 
data in csv format and read it into a MySql (because it was free) data 
base and then did SQL queries to get the data a lot faster.

I realize that not everyone is a data base expert but there are some 
that are fairly easy to use - particularly if you don't need industrial 
strength performance and recovery features.

On Feb 17, 10:46=A0pm, "eeboy" <jason@n_o_s_p_a_m.jasonorsborn.com>
wrote:
> I work for a small manufacturer. We ship a product with several different
> PCB assemblies. We've never had a good system to track exactly what goes
> out the door to each customer. I am in the process of rectifying this and
> wanted to see what others do. At a minimum I want to relate the PCB
> revision and PCB assembly revision as well as the firmware revision back =
to
> a serial number. I'd like to get even more detailed, but I am not sure at
> what point it is too much data/work. I thought of tracking the lot that t=
he
> assembly came from and perhaps even trace this back to the reel of a
> particular component. It would be nice to say "we have a problem with
> component x from lot y... how many boards are affected?". At this point I
> can see it becoming quite complex because we never use an entire reel of
> one particular component on a given lot of PCB assemblies. For example, a
> capacitor from a single reel might be used in several different PCB
> assembly lots (POs). Moreover, since we only assemble the final product
> here and our PCB assemblies are provided turnkey this means we would have
> to rely on our contract manufacturer to provide this data.
>
> So, I was just curious how other manufacturers tracked their products and
> if anyone got to that level of detail. =A0 =A0
>
> --------------------------------------- =A0 =A0 =A0 =A0
> Posted throughhttp://www.EmbeddedRelated.com

We use ICIM and have a module that can 'marry' serial numbers
together. Actually, a parent number (say - the mother board) could get
a cflash and memory stick, and 1 or more PC-104 daughter bds.
'attached' to it. The serial number database is altered, and scanning
any of those numbers afterwards will bring up ALL the asssociated
serial numbers. Internally or if  one come back in for repair. Though,
several of us feel we shouldn't serialize mem sticks and cflash or
basically any 3rd party items we re-sell. We do not serialize
cables,hardware mounting kits, etc. either.

But every 'top level' assembly with a serial number pulled for an
order gets scanned in shipping and 'attached' to the SO and other
shipping paperwork.

Basically, ask yourself why you are tracking and what does the
customer expect. Try not to track accessories, 'throw-away' items or
items that would be re-sent back to your vendor. As for internal
tracking, we use 'work order numbers' which share part of the same
label with the serial number and the text board or product 'name'. So,
internally, we can research the WO if a problem is found in testing,
or, rarely, by a customer failure and take appropriate action
(contacting other customers, reworking/scrapping product still in
stock, etc.) Those situations are rare.

Internal tracking is basically for 2 reasons related to inventory
control and process control/quality. External tracking is more for
warranty duration on returned items, to help with quality/process
problems on occasion, and maybe just to satisfy a customer's
expectations.