Part numbering for manufacturers: smart or sequential?
Most manufacturers do best with short, mostly sequential part numbers plus a small prefix for the item type, keeping description, material and revision in separate fields. Fully intelligent numbers that encode material, size and customer break as soon as something changes. The number identifies the item; the attributes describe it.
Guilherme Rodrigues ItinoseUpdated 2 min read
Key takeaways
- A part number identifies; it should not try to describe everything.
- Use a short type prefix (purchased, machined, assembly) plus a sequence.
- Keep revision out of the part number, in its own field.
- Interchangeable parts keep their number; non-interchangeable changes get a new one.
- Define the rule before migrating to a new ERP.
Part numbers look like an administrative detail until the ERP has three codes for the same bolt and nobody knows which drawing is current.
Sequential vs intelligent
| Type | Example | Pros | Cons |
|---|---|---|---|
| Fully intelligent | ST-1045-D40-L312 | Readable at a glance | Breaks when material or size changes |
| Sequential | 104523 | Never runs out of meaning | Needs a description field |
| Hybrid (recommended) | MC-104523 | Type prefix + stable sequence | Needs a short rule document |
A practical hybrid rule
- Prefix for item type: PU (purchased), MC (machined), SM (sheet metal), WD (weldment), AS (assembly).
- Sequence of five or six digits, issued from one list.
- Revision in its own field and on the drawing.
- Attributes (material, finish, dimensions, supplier code) in ERP fields, not in the number.
New number or new revision?
Use the interchangeability test: if the new part can replace the old one in every product and every stock location, it is a revision. If not, it needs a new number.
Our manufacturing documentation work includes BOM clean-up and numbering rules ready for ERP migration, for industrial manufacturers.
When to outsource this
- Your ERP has duplicate items with different codes
- You are moving thousands of drawings into a new system
When not to
- You have a few dozen items and one person who knows all of them
FAQ
Should the part number include the revision?
No. Keep revision in a separate field. If the part number changes with every revision, purchasing and stock break.
When does a part need a new number?
When the new version is not interchangeable with the old one in every use. If old and new can replace each other, revise instead.
Can I keep supplier part numbers?
Store them as attributes linked to your own number. Your number stays stable even if you change suppliers.
How long should a part number be?
Short enough to type and read aloud without errors; six to eight characters is common.
Send us one drawing
We return a review with issues found, suggested fixes and a fixed-price scope.
