Adam Meyer

Part Number and Revision Schemes

Discussion created by Adam Meyer on Dec 5, 2008
Latest reply on Dec 8, 2008 by Matthew Lorono

My company is implementing PDMWE in a month and I will be the admin for the system. I am trying to streamline our part numbering, revision, and drawing release process and I am looking for feedback or suggestions.

It might be easier to understand our system by first knowing that we design, develop, and manufacture medical devices, and the majority of our parts are injection moulded plastic or silicone parts.

We currently use a numeric/alpha system for revisions.
- numeric (01, 02, 03...) for revisions that are not approved (PPAP's or design verified)
- alpha (A, B, C...) for revisions that are approved (PPAP's or design verified)

Overall, I think this system works well, but are there any concerns with PDMWE?

Our current system uses two schemes for part numbers: one number scheme for pre-production (or development) parts, and a different scheme for production parts.
- the pre-production scheme is XXXX-YY-ZZZ where XXXX is the project number, YY is a sequential number, and ZZZ is the material or colour. Only one drawing is used for each sequential number, so different materials or colours are indicated on the drawing.
- the production scheme is more complicated: XXX-Y-ZZ-AAA (-999) where XXX is the product type, Y identifies it as a component or assembly, ZZ is the product version. If it is a component then AAA is the material or colour and (-999) means that this particular part is also used at our sister company. The (-999) may or may not be in every part number. If it is an assembly then there are other numbers added such as country codes and quantities, but those are controlled in out ERP system and do not relate to the drawing or part.

The distinction between pre-production part numbers and production part numbers is made because not every project goes into production. Another reason for the distinction is that in development we usually build a single cavity tool to develop the design. Once the design is finalized, a production number (with a numeric revision) is given and a multi-cavity tool is built. Once that tool as been PPAP'd then an alpha revision is given.

At this point I don't think changing the part numbering scheme is possible, so are there any issues with respect to PDMWE?

- both the drawing and the part or assembly file names are the first 6 digits of the part number (0645-01.sldprt or 101328.sldprt)

- pre-production drawings are controlled by engineering and are released through a MPD ECO.
- production drawings that have a numeric revision are controlled by engineering and are released through a MPD ECO.
- production drawings that have an alpha revision are controlled by document control and are released through a DC ECO.

Will PDMWE handle two ECO processes?

The following situation is where I'd like to get some feedback.

If an approved part (alpha revision) needs some development work (ie tooling change, new material, replacement tool etc) then a new drawing is released to communicate the change during the approval process. The new drawing part number is the same as the approved drawing, but instead of an alpha revision, it is given the next numeric revision. This allows manufacturing to still use the latest alpha revision until the change is complete. Once the change has been approved, the drawing with the numeric revision is update with the next alpha revision.

To illustrate, the revision block for an approved drawing may look like this:

A .... (was XXXX-YY Rev05)
B ....
C ....

If a change is needed then the next numeric rev is added:

A .... (was XXXX-YY Rev05)
B ....
C ....
06 ....

Once the change is approved then the next alpha rev is added

A .... (was XXXX-YY Rev05)
B ....
C ....
D .... (difference between rev C and rev D)

What do other companies do when production parts need changes that are beyond typos etc?

Sorry for the long post, but I thought it best to have all the information upfront. If you have any comments about how to improve our system or just want to share how you handle these things please do.