Revision control order... what’s your opinion

[Levi31190]

Hello, this is my first post.
So a colleague and myself have been tasked with creating a new PDM work flow that takes our designs from concept to production. We have a difference of opinion.
To not be one sided I will state it freely.


1-So a design is issued for manufacture revision A. This then sits in production status. Samples come back and are inspected. If they come in to the drawing then nothing is done. However if the parts have been accepted out of spec on inspection 90% likely for tolerance get. The part then is put round the modification route putting it in B. This works the same for a modification from this then. It will go up for the design mod and then up for production releasing it.

2- the design is issued out but is held at pre production state, the inspection will be carried out and only when approved and the drawing is in line with the inspection it will be put in production status. Putting the part at A.
The same will happen when in modification. So the part is moved to modification, up a revision. Only when the modified part has the drawing in line with the approved sample will it go to production status.

I hope this makes sense.

If anyone can guide me on this, it would be great. We use solidworks PDM.
Note if you have any work flows your will to share it would be great to see how others work too.
Please share.

 

[Dana]

if a part comes in out of spec that's no reason to change the revision level of the drawing, unless you change the drawing to reflect the "as built" configuration, for example, loosening the tolerances.

We use a "point" revision system. A drawing starts at A.00. There may be several revisions during design or prototyping, they will be A.01, A.02, etc. Once the design is finalized and ready for full production, it becomes revision A. If, later, a change is required it gets bumped to B.00, again with maybe B.01, etc., and again it gets released to production as B.

Minor revisions to a released (drawing correction, no change to the part) are released as A1, A2, B2, etc.

 

[s.weinberg]

You seem to be driving your parts by production, and not the other way around. That seems backwards. The drawing should be finalized and released to production. If you consistently have issues where parts can't be made to match the drawings, you need new designers.
In the event that you decide to change a drawing based on production issues, then that would call for a revision, and then again it should be released to production. Again, this shouldn't be happening all the time or you have bigger issues. If at this point, it STILL can't be made on a regular basis, you have really big issues.

So, it sounds like I'm saying option 1, I think. Also, I typically work with a system similar to what Dana described, except normally revisions are only bumped when releasing to(wards) production, in my experience (with the possibility of it being stopped in the approval process, and going back for another revision before actual release). Typically, I've also used systems where prototypes revisions are, for example, letters, and production revisions are, for example, numbers.