part numbers, how many digits do you have? 2

[mrspetos]

as are company is growing, we are running out of part numbers. currently we have a some-what logical 2 letter and 4 number system (AB1234). i am wondering how many digits other companies are using. also what do you think is more efficient for manufacturing, a logical or random numbering system?

 

[billtati]

What industry are you in?

 

[hendie]

how long is a piece of string ?
210329605 is one, L9603-01-03-02-21 is another, Bellcrank01 is yet another.
Do you want to be able to identify parts merely from the number? how many parts are you going to have ?
everyone will find a particular system suits them over another. You need to find the system that suits you. ~ what's important in a part number ? a) it must be unique ~ all other considerations are merely cosmetic.
Think about what you need, then what you want, then adjust from there.

 

[MikeHalloran]

With 'logical' part numbers, parts are easier to find when you don't have a searchable index, but you run out of numbers sooner, always in just a few 'categories'.

Computerized inventory control and production management systems have trouble with 'logical' or 'significant' part numbers.

Sequential numbering systems, e.g., numbers without significance, make it harder for people to find stuff without the aid of computers, but it's easier for the computers.

An electronics company of my acquaintance used a part numbering system derived from EDN's catalog system; Numbers starting with 48 were for electronic components. The second pair of digits were for a type of component, like resistors. The remaining three digits were assigned in sequence.

Their worst blunder was getting locked into a mainframe- based production management system that limited part numbers to seven digits, so when they had used up 999 numbers for the most common components, they had to start abandoning the significance of the numbering system. It took 20 years for it to become an acute problem, but it was a monster of a problem, because every screen you saw in the system was a separate program, and they were all hard- coded to 7 digit part numbers.

The mainframe programming department thought a backlog of ten years was about right, and started layoffs when it got down to two years. They were part of the problem.

Whatever else you decide to do, make the part number field real wide.




Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[IFRs]

For what it's worth:

We use four digit part numbers for parts that are inventoried.

The 1000 seies are raw materials, the 2000 series are fasteners, the 3000 series are fabricated parts, the 7000 are stainess steel fabricated parts, etc.

If the part has sub-parts that are also inventoried we use 3004-01, 3004-02 etc.

For non inventoried numbers we use FXxxYyyy where the Xxx signifies the category of part and the Yyyy is a sequential number.

 

[mcorker]

Part Numbers are one of my favorite topics. Generally poorly implemented. For a detailed discussion on this please read:

http://www.seradex.com/WhitePapers/Part_Numbering_WhitePaper.pdf

Let me know if you agree or disagree

MC

 

[cfee]

MikeHalloran & mcorker-
Good posts! I read the white paper and I would recommend it as a good starting point.

I'm surprised at how many folks think this stuff can be ignored, and yet are just positive that their solution would be "perfect" for everyone!

Currently I'm managing about 15k parts using some of the ideas in Mike's post and a few creative touches of "my own". I found suggestions in the G-E "Drawing Requirements Manual" (~$200.oo DON'T PIRATE!) to be absolutely life-saving! Our parts exist as part drawings in our system. I use Windows Explorer as my managing system, with little necessity to intersect our MRP system. My aproach of choice is to use a semi-significant numbering system, with the pertinent decision points of the description (in the drawing title line 2) embeded in the file save name. I use an aproach nearly identical to Mike's, and have complete visibility of all files, since I am able to search not only for part number and description, AND ALSO data inside the drawing not included in the save name, but sometimes still necessary.

A combination of Mike's approach, the approach outlined in mcorker's white paper, and attention to salient points made in G-E's manual, and you are certainly on the right track.

Good Luck!
C. Fee

 

[sparky112]

mrspetos,
we use rather large numbers. we also have a large number of possible parts. as a manf'er of food processing machs. each machine is "custom".
we use 5digits-3digits. for example, heat seal assemblys are in the 65000 range, heat seal plates are in the 65500 range.it is further narrowed down to single parts useing the "dash" number.
also purchased parts such as nuts & bolts are given in house part numbers like 52220-125 is a 1/4-20 socket head bolt 1 1/4 long.
this system works good here, and could be easlly adaptible.
i've found alpha numaric systems cumbersom in a computer file system and try to stay away
hope my two cents is of help, good luck

 

[LumpoDelMagnifico]

We use random part numbers for our small parts inventory, All of which begin with PC so you can have PC001234 is a lock washer for a motor bolt and part number PC001235 is a blower fan for a 500Hp Motor. Believe me , the only sensible way to do it is logical part numbers.

For our VFD products, we use a logical part number, this allows me to look at nearly any drive part number and tell the voltage, hp and model of drive from just the part number.

 

[mcorker]

My item number rules for comments:
1) Maximum length is 7 digits
2) All part numbers have the same number of digits - you have sorting issues other wise ie excel will sort like this:
1
10
2
212
30 etc
3) The first 2 or 3 digits are used for grouping ie
PC-0001
PC-0002

 

[mrspetos]

we are currently working on revising our system, i appreciate the recent threads.

we are looking at going with another logical part# system, since it is our culture.

i will post the proposal to get a larger opinon pool.

 

[PeterCharles]

We make bespoke machines from an array of standard parts. So starting at the top level we have a machine mumber (6 digits), machines being a collection of assemblies.

Below machines we have assembly numbers (12 digits) that appear complex but incorporate elements that describe the assembly e.g. the first 3 numbers indicate the size of the machine. Assemblies are a collection of components.

Below assemblies we have component numbers (8 digits). The first four digits describe the type of component e.g. shafts, bearings, wheels and the last four are the individual number.

This seems to work quote well.

 

[mrspetos]

well after deciding to make a logical part number system created a part number over 15 digits long, we have decided to use a random number with family of parts.

all parts will have a less finished part number that is 6 digits long. the first 3 digits note the family tree, ranging from 100-999. the second 3 digits is a random number ranging from 000-999 starting at 000 as we set up new numbers.

the next challenge presented now is how to optimize our description without needing to use a lot of abbreviations or code. shortly stated, to stay away from turning our description into a the logical part number we are changing from because it lacks consistancy.

please give me your input, i am also curious how long of descriptions others carry with their parts.

thanks for all the input.

 

[IFRs]

We use 50 characters per line, two lines. The material database includes both lines. The bills-of-material use only the first line.

 

[mcorker]

Re Description Length

This will typcially be dependent on what your mrp system can accept. Generally I would recommend 250 characters if the software allows.

My Rules of thumb:
1) No abbreviations - otherwise each user invents their own. ie. Fstner, Fsner, Fastnr, Fstnr and Fastner
This makes it difficult to use partial descriptions for searching
2) Hungarian notation - a computer programming concept - where the most important attribute comes first
i.e. Washer, 1/4" not 1/4" Washer
That way all washers are grouped together and not all 1/4" XXX parts. Sizes and colors should come last.
3) Consistent Attribute marker - ie use Washer, 1/4" or Washer - 1/4" but be consistent
3) Conventions need to be established where multiple attributes are in the description - ie 2" Stainless Steel Angle. Do you want all angle sorted together or all stainless steel.
4) No units of measure in the description - thsi should be in the uom field and with uom conversions - ie. don't put Masking Tape, Case of 20 Rolls
5) Use Proper Case Formating

Angle, Stainless Steel - 2" is easier to read than

ANGLE, STAINLESS STEEL - 2"

My 2 cents

Mark Corker
ww.seradex.com

 

[SteveSmith]

We us an 8 digit system. The first 3 digits are a part class followed by a dash then 4 digits that are chosen sequentialy in most cases.

Examples:

219-0119 - the 219 is the Circuit Breaker catagory with the 0119 being the 119th number used.

518-0506 - the 518 is the Plate catagory with the 0506 being the 506th number used.

128-0029 - the 128 is the Bearing catagory with the 0029 being the 29th number used.

564-1029 - the 564 is the resistor catagory with the 1029 being the 29th number used in the 1% metal film sub-catagory.

I would actually prefer an additional 3 digits (-xxx) so that we could put the 400+ 1% metal films on 1 CAD drawing say 564-1000 with the -xxx representing each value. The 100 ohm 1% metal film would be 564-1000-097 for example.

 

[SomeYahoo]

Steve -

In the case that you are talking about, we typically make the "xxx" part of the actual part number. We would have the drawing 564-1xxx and the parts 564-1000 through 564-1999 would be contained in the one drawing in tabular form.

Just an idea.

 

[PeterCharles]

"My Rules of thumb:
1) No abbreviations - otherwise each user invents their own. ie. Fstner, Fsner, Fastnr, Fstnr and Fastner
This makes it difficult to use partial descriptions for searching"

True in my experience. But if you have to use abbreviations then document them and if you can, use just a small number of people to actually fill in the data!

"2) Hungarian notation - a computer programming concept - where the most important attribute comes first
i.e. Washer, 1/4" not 1/4" Washer
That way all washers are grouped together and not all 1/4" XXX parts. Sizes and colors should come last."

Never heard it described as Hungarian notation, but equally true from my experience.

"3) Consistent Attribute marker - ie use Washer, 1/4" or Washer - 1/4" but be consistent
3) Conventions need to be established where multiple attributes are in the description - ie 2" Stainless Steel Angle. Do you want all angle sorted together or all stainless steel.
4) No units of measure in the description - thsi should be in the uom field and with uom conversions - ie. don't put Masking Tape, Case of 20 Rolls
5) Use Proper Case Formating "

So much good sense here. My experience was based on :

an old computer system limiting field length. BAD
limited field length forcing abbreviations. BAD
documented procedure for creating new part numbers. GOOD
selected people only to create new part numbers. GOOD

Finally, even if forced to compromise think ahead to allow for future expansion. 12/345 may seem enough now it would not be too hard to update to 012/345 in the future.