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How intelligent should part numbers be?

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Part number systems are as unique as the companies that use them, and for a long time, many engineers have discussed whether to use intelligent or generic part number systems.

So, what are intelligent or generic part numbers?

An intelligent part number contains human identifiable information, it may be size, colour, material, project or some other important information relating to your parts.

Whereas a generic part number is a number of a set length that runs part of a sequence, this is where it differs from the intelligent part numbers as it’s hard to know one part from another just by the number alone, as there is nothing to relate to.

What system should I use? Generic vs Intelligent part numbering systems

Let’s use a 10mm hex head bolt that’s 55mm long, made from Stainless steel as an example part to explore these systems

An example of a generic part number is


The problem is on its own this part number cannot be understood just by looking at it, you need to look it up somewhere like a database, spreadsheet or have a very good photographic memory.

Whereas an example of an intelligent part number is


If the part number rules are known this quite clearly shows the main variables of the bolt required to understand what this part is, i.e. type-diameter-length-material.

If you had to look for several different bolts its clear what system seems easier to use.

With bolts, they have pretty simple attributes, and if a bolt is shorter or wider it becomes a new part number.

But what happens if your customer now requires a different thread pitch for the same size bolt, the pitch is not stated in the part number so how do you deal with this change?

Do you have to change all of your existing part numbers to now contain the pitch as well?

Do you amend just the single part so you have different variables in the part number on different parts? Thus, changing the system, then what system do we use moving forward?

My point being is you have to choose your variables carefully when using an intelligent part number system as small unaccounted-for changes, can break your system, making you have to make an exception for the part or redesign the whole system again.

So, there are pros and cons to both systems and depending on your company’s products or how they use these products, depends on what system or combination of systems you will need.

Project (Generic) based numbering systems

Some companies will work on projects and will be assigned a generic project number, and this will be used as a section of the part number, this is using a two-section generic part numbering system.

An example of this would be


This would show the number P00695 as the project and 001 as the individual part number for each part or document within the project.

The benefit of this system is you can track all of your parts associated with that project by searching for P00695

The disadvantage is, if you would like to use this part on another project, it would look out of place to use the number P00695 on the P00952 Project.

So, one way around this that car manufacturers commonly use, is to assign a new part number to the same part. So that the single part will have multiple numbers assigned to it.

Hybrid based numbering systems

Hybrid systems are a combination of both intelligent and generic systems.

Using VW as an example, they have a 9-digit part number system as seen below.

DIGITAL BIRTH - Part Numbers

Each section can be broken down as follows

Type & Model/Version (3 digits)

This would be an intelligent number in relation to the type of vehicle, for example, VW Beatle = 115.

Main Part Group (1 digit)

This would be an intelligent number in relation to the Main Assembly groups split into 10 numbers, for example, 1= Engine and 8= Body Parts and Interior Trim.

Part Sub-Group (2 digits)

This would be an intelligent number in relation to the Sub-Assembly groups split into and up to 99 sections of the Main assemblies, this would be broken up just like the Main Part groups were before.

Component Number (3 digits)

This would be a generic number system with a few associated rules applied

Major Assemblies begin with a Zero Handed parts must be odd and even on the last digit (105 Left side / 106 Right side) The lower the number the closer to the front of the vehicle it is In any group of parts, the higher the number, the larger the part.

Modification Code (up to 3 letters)

This would be linked to the revision of the part to track changes.

As you can see the part numbering system can become very complex, especially as you introduce more rules to the system.

A part numbering system for a car that has many different parts, sub-assemblies and main assemblies to manage, will require a very robust system with lots of different combinations.

As car companies deal with lots of parts that are massed produced and not custom parts that are rarely reused, the main part of their number is intelligent based, they also retain flexibility with the numbering system all the way until production to iron out any crossover or conflicts with part numbers, and assign new numbers to identical parts for different models of car.

How revisions and part numbers may influence each other

We noticed in the last section that the Modification code or Revision was used as a section of the part number, so let’s take a deeper look because parts can change, it’s a fact of life.

When revising a part, should you include this in the part number?

Parts usually have a part number and a revision, they are separate items of information.

If a part is revised, but they continue to retain the same fit, form and function as the previous part, it should retain the same part number.

This will prevent you from having to update your documentation and customers of these changes.

A good test of this would be, could you put both revisions of the part in the same bucket to be used? If yes revise the part, if no, the part needs a completely new part number.

Supplier/Customer vs Internal Part numbers

Many companies state that when designing a parts system that they can use the Supplier or Customers part number to identify their parts.

The problem with this is that suppliers and customers can change their numbers without warning making your information obsolete.

By having your own number system and using their part numbers as metadata alongside you internal part numbering system you can maintain control over identification of the parts.

Designing a part number system

It is important to understand your business, before designing a parts numbering system, here are some examples of what system you may use.

If you make custom parts regularly and want to reuse parts on different projects, a generic part number is probably best to use,

If you do not reuse parts a project number based system may work.

If you mass produce large amounts of repetitive and similar parts an intelligent system may be more suited.

These are not hard fast rules, you will need to discover what system works best for you.

System Custom Parts Repetitive Production Parts Reuse Parts on different projects Similar Parts (bolts / resistors)
Generic X X
Project based X
Intelligent X X X
Hybrid X X X

Part number desirable features

  • Easy to generate part numbers – the junior should be able to do it
  • Longevity – part numbers will be able to with stand multiple parts and not break the system
  • Readability
    • Keep numbers the same length
    • Break up long numbers with dashes
  • Uniqueness – no two numbers should be the same
  • Meta Data – use extra data to support the part number
    • Description
    • Weight
    • Length
    • Purchase part
    • Manufacture Part Number
    • Revision
  • Consider leaving gaps in between part numbers for future developments.

Before launching your new system, gather up some parts, or new quotes for parts and get the new guy to number them using your system.

If all goes to plan you set and ready to go.

Good luck!