SonicFlow
Mechanical
- Mar 8, 2007
- 15
I working on implementing a PDM system, and I think we should use straight alpha Revisions, and not skip any letters.
The opposing side wants to follow the ASME guidelines and skip I, O, Q, S, X and Z. I would be more satisfied with this if someone gave me some good arguments on why this is so important. With or without a PDM system skipping letters introduces additional complexity, and it is often not consistently maintained around the organization.
The way I see it - there is little opportunity for confusion if we do not skip letters. So what if a machine shop thinks it is revision "1" (ignoring the G and H showing on rev table) if they use the right drawing? (One little idea - for drawing rev letters we could use a font that makes it more clear that an I is not a 1.) Our prototype numbers are 01, 02... two digit numeric counter.
Skipping letters correctly becomes an esoteric tribal knowledge sort of thing that will require a group effort to maintain. I say tribal, because even if it is written down people have to remember to go look at the spec, and who wants to do that day-to-day? People often forget some of the these letters.
Going forward Enterprise PDM will make things in the vault have the correct sequence, but there are plenty of other activities. For one thing, our ERP gives no guidance on this issue (and PDM and ERP will not be linked at this stage). Historically we have not even consistently followed the ASME system in engineering. I and O were often skipped, but Q, S, X and Z were often not. I and O are easier to remember (and far more frequently reached). I must admit it bothers me a bit to use I or O. We could compromise and just skip I and O, make that our system... or get rid of the whole, perhaps overblown, convention.
Yes, we can teach people to follow the system more, but is it worth the effort?
Serious Question: For PDM migration - Do we bump legacy documents up a rev letter if they have one of the forbidden letters? Release new rev with an ECO? We probably have several hundred drawings with forbidden revision letters.
Overall I think it is not worth the trouble!
Thanks for any opinions, rants or examples.
The opposing side wants to follow the ASME guidelines and skip I, O, Q, S, X and Z. I would be more satisfied with this if someone gave me some good arguments on why this is so important. With or without a PDM system skipping letters introduces additional complexity, and it is often not consistently maintained around the organization.
The way I see it - there is little opportunity for confusion if we do not skip letters. So what if a machine shop thinks it is revision "1" (ignoring the G and H showing on rev table) if they use the right drawing? (One little idea - for drawing rev letters we could use a font that makes it more clear that an I is not a 1.) Our prototype numbers are 01, 02... two digit numeric counter.
Skipping letters correctly becomes an esoteric tribal knowledge sort of thing that will require a group effort to maintain. I say tribal, because even if it is written down people have to remember to go look at the spec, and who wants to do that day-to-day? People often forget some of the these letters.
Going forward Enterprise PDM will make things in the vault have the correct sequence, but there are plenty of other activities. For one thing, our ERP gives no guidance on this issue (and PDM and ERP will not be linked at this stage). Historically we have not even consistently followed the ASME system in engineering. I and O were often skipped, but Q, S, X and Z were often not. I and O are easier to remember (and far more frequently reached). I must admit it bothers me a bit to use I or O. We could compromise and just skip I and O, make that our system... or get rid of the whole, perhaps overblown, convention.
Yes, we can teach people to follow the system more, but is it worth the effort?
Serious Question: For PDM migration - Do we bump legacy documents up a rev letter if they have one of the forbidden letters? Release new rev with an ECO? We probably have several hundred drawings with forbidden revision letters.
Overall I think it is not worth the trouble!
Thanks for any opinions, rants or examples.
