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RE: gEDA-user: Master Parts List



John and all,

FWIW and slightly off topic:

IMHO your way ahead on most of us in categorising pcb footprints according
some naming convention (of your own) which is slightly differing from IPC
and may be even better, see your own note on this subject ;-)

I think that a particular convention for a master parts list is better than
"misc" or a "Yet Another Insignificant Number Scheme", and is allways better
than no convention at all.

If one looks for a capacitor, "C" or "CAP" come to mind.

Categorising by such a scheme makes sense in a designer environment.

Since gEDA is aiming for this particular environment this looks natural to
me.

You just can't please everybody, let's please "our own kind" (narrow minded
vision here ;-)

If a buy out / aquisition occurs it's the problem of the buyer, and may be
subject to negotiation.

If one needs a "Yet Another Insignificant Number Scheme" for the people in
the warehouse dept: in any database there is probably an integer index
pointer allready available.

Just my EUR 0.02

Kind regards,

Bert Timmerman.

-----Oorspronkelijk bericht-----
Van: geda-user-bounces@xxxxxxxxxxxxxx
[mailto:geda-user-bounces@xxxxxxxxxxxxxx] Namens John Luciani
Verzonden: woensdag 28 februari 2007 4:34
Aan: gEDA user mailing list
Onderwerp: Re: gEDA-user: Master Parts List

On 2/27/07, Bob Paddock <bob.paddock@xxxxxxxxx> wrote:
> On Monday 26 February 2007 17:17, John Luciani wrote:
On Monday 26 February 2007 17:17, John Luciani wrote:
>> I am putting together a master parts list table for my component 
>> database.
>
>> The categories CAP, RES, IND, DIO, LED, BAT, etc. would work.
>
>Don't try to force inventory into a category system.  It makes sense in 
>the beginning when you only have a few parts, but has your 
>system/business grows it rapidly falls apart.  May Heaven help you if 
>there is a buy out/acquisition, where two category based systems 
>collide.
>
>Consider an  multifunction widget.  What category do you put it in?  
>You end up with a "Misc" category, which rapidly grows.
>
>Assign non-significant part numbers to each part, such as 00001 for the
first
>part, or perhaps related to date&time.   That part number
>appears in BOM.  That part number is the referenced throughout to print 
>the fields of interest, at the point of interest.  The purchasing 
>department has vastly different interests in some fields than, do the 
>people in the warehouse, or the engineering department.

I agree that it is impractacle to embed all of the fields of interest for
all of the departments into the part number. I was hoping to embed some of
the fields related to electrical engineering. At the last company I worked
for they had a two or three digit component group prefix followed by a
series of digits. Sometimes the series of digits related to component
attributes and other times it was just an ordinal.

>
>> For example a 330pf 1% X7R ceramic cap in an 0805 package could be
>> CAP_X7R-331-102-0805
>
>Playing devils advocate here:  Does the above part number tell you if 
>you can substituted a part of "form/fit/function"?  Has that part been 
>used in a regulator drawings; think FDA?  If it has you can't change 
>substitute it even if it meets "form/fit/function" etc.
>To make matters worse has it been used in more than one regulatory 
>environment like both FDA and MSHA?  Did some bureaucrat just come up 
>with some new regulation that cuts across all categories; think Lead 
>Free?

It is unlikely that any part number scheme is going to allow you to make
"form/fit/function" substitution decisions. For that you will need to lookup
component specifications. My plan is to have a table that relates
CAP_X7R.... or part number 000001 to various manufacturers parts that meet
the specification. Regulatory information would require additional tables.

>
>> A few other caps --- CAP_NPO, CAP_AE (aluminum electrolytic) Cap 
>> arrays --- CAPCAV, CAPCAX, CAPCAF
>>
>> For ICs maybe IC_AMP, IC_LDO, IC_74LVC138, etc. Some sort of package 
>> suffix convention is needed.
>
>I think your already seeing why the category system fails as it expands.

I agree that these categories are getting close to the infamous "misc".
Assigning ordinals to the part numbers makes everything "misc" from the
start;-) I was hoping there was something between an infinite number of
categories and one category with an infinite number of parts ;-)

>
>There are several Open Source ERP systems these days, take a look at 
>them.  I'm still doing that myself.
>
>From the Been There Done That "Category" with 175,000+ parts, at my 
>former place of employment.

Have you seen any documentation for part numbering schemes in any of these
Open Source ERP systems? Could you post the URLs ERP systems that you have
found?

Thanks.

(* jcl *)
--
http://www.luciani.org


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