Setting up part numbering for a machine builder
For warehouse, work preparation, purchasing and owners of machine builders and contract manufacturers.
Short answer
Set up part numbering with a short code for the main group and a sequence number, for example HY-0012. Put all other attributes, such as type, size, material and supplier, in separate fields and not in the number. Use a fixed order for the description (what – type – size), give the supplier part number its own field, never reuse a number, and start with the items that move most often. Assigning a number is then a fixed rule: the next free number in the group. You need no AI for that.
In short
- Main group plus sequence: short, stable and easy to sort.
- Attributes in fields, not in the number. Otherwise the number is wrong as soon as something changes.
- Description always in the same order, so you can find duplicates.
- Start with what moves, not with the whole warehouse.
1. Meaningful or meaningless number?
There are two ways to make part numbers. A meaningful (intelligent) number tells you something about the item, for example HY-SL-2SN-08-2000 for a hydraulic hose of a certain size. A meaningless (non-intelligent) number is simply a sequence, such as 104233.
Meaningful number
- You recognise the item from the number
- Easy to sort by type
- But: if size or supplier changes, the number is wrong
- But: someone has to know the rules to create a number
Meaningless sequence
- Fast, error-free new number
- Stays valid forever
- But: the number doesn't tell you what it is
- But: you can only search by description and attributes
For most machine builders a middle way works best: only the main group in the number, followed by a sequence. HY-0012 tells you it is hydraulics, and stays valid when the supplier or size changes. Everything else lives in fields you can search and filter in your ERP.
2. Five rules to keep
- 1
One item, one number
Never reuse a number, not even when an item is discontinued. Set it to the status Discontinued.
- 2
Only the main group in the number
Size, type, material and supplier go into fields. Otherwise the number is wrong as soon as something changes.
- 3
Supplier part number in its own field
Then you can search on both, and switch suppliers without a new item number.
- 4
Description always: what – type – size
For example "Hydraulic hose – 2SN – 1/2" × 2000 mm". That way you find duplicates before they are in the system.
- 5
Start with what moves
Not the whole warehouse at once, but first the items used in the past year.
3. Try it: the next free number
Pick a main group and fill in what, type and size. The generator gives the next free number, blocks an item that already exists and warns when an item looks like what you enter. The list is fictional.
Part number generator
| Number | Description |
|---|---|
| HY-0001 | Hydraulic hose – 2SN – 1/2" × 2000 mm |
| HY-0002 | Hydraulic pump – gear – 16 cc |
| HY-0003 | Next free number |
4. Main groups for a machine builder
Keep it to six to twelve groups. Too many and people doubt where something belongs. Too few and a group becomes a dumping ground.
| Code | Group | What belongs here |
|---|---|---|
| ST | Steel and plate | Plate, tube, pipe, strip, sections |
| MD | Made parts | Own parts made to drawing |
| AA | Drive | Bearings, motors, gearboxes, chains |
| HY | Hydraulics | Hoses, couplings, pumps, cylinders, valves |
| PN | Pneumatics | Cylinders, valves, hose, fittings |
| EL | Electrical | Switches, relays, cable, sensors, cabinets |
| BV | Fasteners | Bolts, nuts, washers, pins |
| VB | Consumables | Welding wire, gas, grinding discs, paint |
Own made parts
Give a made part an item number in the Made parts group, and put the drawing number and revision in their own fields. Then the item number doesn't change with a new revision, and you can still always see which drawing belongs to what is on the shelf.
5. Cleaning up an existing list
- 1
Export what exists
Pull all items from the ERP or warehouse file, including usage over the past year.
- 2
Pick what moves
Filter on items used in the past year. Start there. The rest comes later, or is discontinued.
- 3
Rewrite the descriptions
In the fixed order what – type – size. This is most of the work, and this is where AI helps most: a proposal per row, approved by a person.
- 4
Find duplicates
Sort by description. The template flags duplicate descriptions in red. Merge them into one item.
- 5
Assign group and number
Per item the group and the next free number. Keep the old number in its own field, so searching on the old number keeps working.
- 6
Decide who creates new items
One or two people, with the five rules. Otherwise the list fills up again within a year.
Where AI does help
In the one-off clean-up of what is there now: rewriting old descriptions, proposing a main group, and finding items that look alike but are written differently. AI proposes, a person approves. After that, numbering is just a rule.
Frequently asked questions
Should the size be in the part number?
Preferably not. Put the size in its own field and in the description. If the size is in the number and the size changes, the number is wrong, or you end up with two numbers for almost the same item.
How many digits does the sequence need?
Four digits give 9,999 numbers per main group. For most groups in a machine builder that is enough. If you expect more items in a group, choose five digits. Decide once and keep it the same everywhere.
What do you do with the old part numbers?
Keep them in a separate field, for example 'old number'. Then people can keep searching on the old number for a while, and you can still find old drawings and orders.
Can the ERP assign numbers automatically?
Most ERP packages can keep number sequences per group. Ask your vendor or consultant how that works in your version. The groups and rules have to be fixed first.
Do you need AI to assign part numbers?
No. The next free number in a group is a fixed rule. AI is useful for the one-off clean-up of a messy list: rewriting descriptions and finding duplicates.
Sources
Other people's figures and statements on this page come from here. Calculation examples are fictional.
- Arena Solutions: Part numbering best practices Overview of intelligent and non-intelligent part numbers and when to choose which.
- OpenBOM: Part numbering best practices Why intelligent numbers become hard to maintain as a company grows.
About the author
Safouan Bolbaroud · Founder of Agentfabriek
At Agentfabriek, Safouan builds automations on top of the ERP systems of manufacturers and wholesalers. He writes about what needs to be in order before automation makes sense.