Any have any perfect part numbering systems?

[KENAT]

My group at work has been given the job of coming up with a new part numbering scheme so we can more closely align activities between a few of our divisions.

At the moment the two main sites both have their own ‘smart’ numbering scheme.

Also every part used has to have a company number assigned. Not just parts for which there are drawings but also hardware etc. (don’t get me started)

We buy in a lot of components but historically they haven’t created SCD/VCD etc for most of these although we’re thinking maybe they should.

Our first idea was essentially a dumb, sequential numbering scheme for all drawings, with maybe some kind of smart scheme for the standard hardware.

We’ve been told by materials that we need to maintain some smartness because they find it helpful.

Anyone have any good examples of numbering schemes they’d like to share?

 

[swertel]

Smart numbering systems don't work. Invovaton and development will cause you do develope something you didn't consider and therefore won't fit within the smart numbering system.

Completely insignificant part numbering systems pose the issue, as you state, that no one can look at the number and know - even generally - what the part is.

Semisignificant parts are the only way to go. Without knowing you product lines, I can't help device one via eng-tips. Contact me privately if you want to delve into some deep ideas.

http://wertel.eng.pro

But, in general, standard hardware items can be fully smart because they don't change: fasteners, washers, adhesives, etc.

You should development a means to identify other purchased parts from your vendors rather than using their part numbers. Although I prefer using vendors' part numbers, there could a potential part number duplication - thus causing confusion. Creating your own number and cross-referencing the vendor info also give you a place to capture vendor information in addition to your buy cards.

Finally, I like the most simple classification system. The part number has a prefix identifying the product it belongs to and then an insignificant sequential number. That's it. Some people like adding additional prefixes for castings, extrusions, sheet metal fab, machining, etc., but if you change materials or manufacturing methods, those ID's foul up the system.

Good luck, this is not an easy task. Don't forget about configuration management!

--Scott

--Scott

For some pleasure reading, try FAQ731-376

 

[KENAT]

We kind of got landed this by configuration management so don't worry, they wont be forgotten!

Thanks for the input.

 

[ewh]

Scott's advice is good; limit any significant digits. KISS.

 

[ctopher]

I agree with Scott. (Except for some spelling errors)

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[drawoh]

KENAT,

I agree with Scott too.

My experience with intelligent numbers consists of watching non-technical clerks input the data in a panic rush. There were lot of errors. The original classication system was not very good anyway.

Consider what happens when your resistor gets classifed as a screw. The number gets all over BOMs and purchase requisitions and configuration management refuses to change it. Your intelligence ceases to be intelligent.

Any classification of parts should be a database field separate from the part number. This allows you to correct mistakes, and otherwise change classifications as you re-orgainize your system.

JHG

 

[aardvarkdw]

Our system uses a thre part numbering system which seems to work well 90% of the time.

We use a 2 or 3 digit prefix to identify the item category

Then we assign an arbitrary 6 digit number to the part

Then we have a 3 digit version number at the end.

We then will have a revision associated with each part.

It looks like this XXX-XXXXXX-XXX rev.A

It can be confusing when you first start out and like swertel said innovation and unforseen component categories have caused us a few problems as well as engineers that have a different idea of how a part should be classified, but all in all it works. Something similar may work for you.

 

[ctopher]

I suggest using a PDM software and remove "rev.A". It would make it much easier and more efficient to work with the files.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[KENAT]

Thanks everyone for your input.

Just to make it clear, with the exception of possibly hardware most of my team would prefer a dumb numbering system.

However, our 'customers' in materials (purchasing), and probably other areas once they see our proposals, want some smartness.

We're proposing something like xx-yyyyyy where xx is the 'smart' category and yyyyyy is just a unique identifier (not sure yet if it will be totally unique or just unique to that category).

We don't want to identify by project or our product line because so many times a part is used several places over time.

What purchasing wants though is categories which correspond to individual purchasers/supplier specialties. So break down between machined metallic, machined non metallic and sheet metal (our 3 main areas, not much casting or forging or moldings etc). Obviously though changing/options in manufacturing methods can mess this up.

For drawings there will be a rev number, the PDM system we're looking at does put it in the file name (as best we know).

drawoh, we regularly see the problems you mention, part of the reason for us preferring dumb.

We also thought our new ERP system SAP (Stops All Production) would be able to handle the categorization but seems we were over optimistic.

There’s probably more I could add but I’ve already taken up plenty of your valuable time. Any ideas or input is appreciated though.

 

[drawoh]

aardvarkdw,

Revision and version numbers should not be included in part numbers. When you allow this, you imply that I can check out drawings and make changes to form fit and function. If you use the same part in several places, I can create a serious mess.

You should note drawing revision numbers on your purchase and work orders. This provides a history of what you did on any given day. This should not be in your database.

JHG

 

[KENAT]

Basically what we have as part of our ECO process is that if there is a change of 'function form or fit' and the part isn't 'backward interchangeable' then it gets a new part number. (I think in mil std stuff it comes down to class 1 2 etc) To keep the same number and just change rev it has to be backward compatible.

From my experience rev (or issue in the UK) isn't intrinsically part of the drawing/part number as such, it is an additional identifier.

Obviously having one assembly that requires rev B and one that requires rev C is a bad idea.

 

[ctopher]

Just my 2 cents.
I wouldn't allow purchasing to set engineering standards. The engineering dept & QA should decide on part numbering system, not purchasing or marketing. They will cause you grief in the long run.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

 

[ewh]

I agree with Chris. If they want control, let them assign their own inventory numbers.

 

[KENAT]

Ctopher/ewh That's how I'm used to it being done but this place doesn't seem to work that way. Our Engineering dept isn't even all together, let alone all the other departments. And then we've got to do it across not just our site but two others as well who currently have their own systems.

I don't know if it's the difference between commercial and defense or between US and UK or if this place is just out on its own, but it's frustrating.

Getting some of the inputs from you guys and the others in my group helps keep me sane. Otherwise I'd think I'd been off in my own little world in my career so far.

 

[CorBlimeyLimey]

Lots of good info' in Drawing numbering system thread559-45542


Helpful SW websites FAQ559-520
How to get answers to your SW questions FAQ559-1091

 

[KENAT]

Thanks CorBlimey,

I briefly looked it over. A few of the same posters and similar suggestions! Plus a few that made me wince.

One thing I did notice on that thread and that has started to come in here is a lot of the talk was about CAD file names.

I'm talking about part numbering, not necessarily CAD file names.

Whilst we do anticipate that our file names will follow the part numbers the first nut to crack is the part numbering (while keeping the file name in the back of our minds).

Also for parts/assy we design I don't think having the part number the same as the drawing number is a problem.

 

[swertel]

I'm talking about part numbering, not necessarily CAD file names.

Thank you. It is so refreshing to see that some people are actually capable of making this distinction.

Kenat, it also appears that you have a very good grasp of configuration management. You are already well versed in the fact that revision changes should be tracked and the history files kept. You also know that a change to form, fit, or function (part is no longer interchangeable) requires a new part number and not just a rev bump.

Since you are already so well versed in these matters, I'm sure you are also well aware that your part number, file name, drawing, number, and internal identifier do not have to be one and the same so long as you can each one.

For example, you can have part number YYYYYY. Very simple configuration management number that is insignificant and will last you through the years.
The file name can by YYYYYY.RevA without issue.
The internal identifier, i.e. purhase order number, inventory and tracking number, etc. can by XXXX-YYYYYY-ZZZ.
The drawing number can be the same as the part number. I have yet to come across a drawing numbering system that didn't match the part number. There is also nothing stopping you from putting the XXXX and ZZZ information on the drawing - even in the title block!

How does this all play out in the end? Your part number is your configuration management number. It never changes. But, everything else is just tracking information. If you change manufacturing processes and you XXXX or ZZZ end up changing, a rev to the part/drawing to change this info and you're golden! Since you didn't change the actual part number, you don't have any worries about maintaining configuration management by changing your internal identifiers. You just have to make sure your standard operating procedures are written such to specify the part number and do not let the culture of the company dictate that XXXX-YYYYYY-ZZZ is the part number, only the YYYYYY.

Sorry for the length. Thus why an email outside this forum may have been better so I can fully understand your product and needs.

--Scott

For some pleasure reading, try FAQ731-376

 

[KENAT]

Thanks Swertel,

I did follow your earlier link but it looked like you do consultancy and I don't think we have any budget for external help and I didn't want to try and take advantage.

The others in the group and I all have defense type backgrounds, and were brought in due to our experience with standards etc to address issues like this. Often we get complaints that what applied in defense doesn't apply to commercial. So I post on here to see if I can find out what other people, especially more commercial, think/do.

We were hoping the part type differentiation could be done/handled in MRP, which would support the kind of scheme you’re proposing, but it seems we may have been wrong.

Maybe I had the title of the post wrong. Should have been least bad not perfect!

 

[MadMango]

What type of MRP/ERP system do you have? We have a very old system (new in 1997), and it allows for identifying the responsible purchaser and planner, also if the part is manufactured or purchased, as well as if it is sheet metal, machined, hardware, fastener, etc. This type of information should not be incorporated into the part number.

[green]"Art without engineering is dreaming; Engineering without art is calculating."[/green]
Steven K. Roberts, Technomad
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[KENAT]

SAP

I'm not so sure it's an SAP problem as to how we've chosen to set it up and use it.

Also whilst we are (at least for now) standardizing our part numbering across one division (several sites) we have another division (also several sites) & corporate who use SAP.

I guess their requirements may be driving some of the SAP issues.