Forums

Manufacturing - Tracking

Started by eeboy February 18, 2011
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.	   
					
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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.