Identifying DoD Level 1, 2, or 3 on Drawing Face

[swertel]

We used to identify the design maturity level based on part number. Now, we are eliminating that business process and will be maintaining the same part number throughout the entire development cycle. Therefore, we would like a method to identify the Design Maturity on the face of the drawing.

After several internet search iterations, I haven't found a good example. I have my own idea, but I'd like to compare it to, or borrow from, existing examples. Does anyone have a good drafting standard (title block or template) to identify design maturity level on the face of a drawing?

Thanks,

--Scott
www.wertel.pro

 

[KENAT]

I don't think it will be any help but recent thread431-353974 touches on mil-std drawing levels.

Former UK defense company. When the drawings were under our control we kept them at alphabet revisions - even at this stage though they were under a fairly robust internal drawing control system. Once the govt had approved the design and it was effectively locked down we in theory changed to numeric revisions. In practice the govt was getting less & less keep on paying for rev changes of all drawings in pack so often they only went to '1' if there was something else driving a revision.

Now in the US commercial we use numeric revs for prototypes, moving to rev A at formal release. While at numeric values there is virtually no formal drawing control, basically up to the individual draftsman/engineer to keep track.

Not sure if that helps any. I think vaguely similar has been discussed before but I forget on which forum.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[swertel]

I tried the revision as a deliminator of status, but I got shot down from my Teamcenter administrator. The affected departments loved the concept, though. Too bad I couldn't implement it beyond the pilot program.

Thus, I now have to put a I, II, or III somewhere on the face of the drawing. I'm thinking just a small block in the upper left near our Proprietary statement and ITAR/EAR note.


--Scott
www.wertel.pro

 

[ctopher]

We do the same as KENAT.
I have never been to a company that has used I, II, or III on a drawing.
I work at a large company. A newbie here tried to implement it, was shot down. It's not understood by anyone here, or any of our customers or suppliers.

Chris, CSWA
SolidWorks 14
ctopher's home
SolidWorks Legion

 

[JNieman]

My experience mirrors KENAT. In doing work for oil/gas at a structural engineering firm, all my designs were alphabetic in the preliminary stage. When we were approved to "issue for construction" then all alphabetic revisions were deleted from the revision block, a revision level of "0" (zero) was put in with the description "Issued for Construction" and anything after that was numeric.

Now that I'm back in the manufacturing world, it is flipped. We do a rev "-" (dash) for initial release (which irks me) and numbers for preliminary design stages, and letters for post-release revisions. Before I got here, there was little-to-no control over preliminary revisions. Since letters were used for revisions post-release, numbers was my only option.

I very much like the two-stage revision standard of numbers/letters.

_________________________________________
NX8.0, Solidworks 2014, AutoCAD LT, Autocad Plant 3D 2013, Enovia DMUv5

 

[ewh]

Ditto my experience on military contracts. Drawing level was never specified on the face of the drawing, but in other documentation.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV

 

[3DDave]

Drawing level is indicated by signatures or release level - it's ready to go or it isn't. Even the military distanced itself from level #s a while ago. I forget what they switched to, and many people still refer to level 1, 2, and 3.

The only purpose the description had before was to tell how much drafting effort remained / should be paid for. Level 3 drawings were typically redrawn by drafting onto a durable, reproducible material like mylar or (older) linen using durable, non-smudging plastic lead or ink. Level 2 was usually pencil on vellum by engineers or designers and level 1 was paper or cocktail napkins or something.

I guess no one needed to mark the drawings as two things made its state obvious - was it drawn on a durable material and was it signed off.

 

[swertel]

Level 1, 2, and 3 have translated into Conceptual, Development, and Production.
And the difference has continued to evolve on the same premise, but includes more than the level of detail of the drawing. It includes approval processes and affects on other downstream departments.

I. Conceptual A conceptual drawing is a sketch, on a napkin or otherwise, even CAD, but doesn't require full definition and only the person creating the sketch approves/releases it. It is used to convey a concept or for a proposal. There is no checking or other reviews performed on the design.

II. Development A developmental design is a step above that. It has been detailed out, but maybe not a tolerance analysis performed. It has been reviewed by at least a checker and probably has some input from the integrated program team to verify sources, manufacturability, preliminary quality control plans, etc. Some details may be left TBD until testing or qualification is performed to fully define the design. Things like material specifications, final tolerances, and other general notes may not be complete.

III. Production A production design is a the final step. All the i's are dotted and t's crossed. The entire IPT has to review and sign off before it is released. There are no gaps in the design left to the imagination.

The reasoning behind showing a I, II, or III (or a C, D, or P) on the drawing when there are no other human readable identifiers on the drawing (such as part number or revision) is to know the level of rigor applied to release the drawing. We don't want a Production Planner pulling a concept-level design and having Supply Chain order hard tooling and 100,000 parts. We also don't want an engineer using a concept level component on a production level assembly and assume it has been checked and validated when in actuality it has not been. That could be dangerous with deadly consequences.

--Scott
www.wertel.pro

 

[3DDave]

That's the problem - anyone can show any symbol on any drawing; it doesn't mean any of the supporting functions has been done. The control needs to be elsewhere. Otherwise, how does one prevent pulling III Rev A and sending that instead of a III Rev B? Or someone copies an existing drawing to make a similar part of a slightly different size and forgets to change from III to I? Include the Production Planner in the IPT and that should resolve most of the problems you might run into.

 

[ewh]

I agree with 3DDave... there is no real configuration control if you have to rely on a letter or a symbol on a drawing to determine if it is the correct one to manufacture to. There should be controls in place ensuring that manufacturing (whether in-house or subbed out) has ONLY the correct, current documentation. Superceded documentation should never remain on the shop floor. To operate otherwise is asking for trouble.

“Know the rules well, so you can break them effectively.”
-Dalai Lama XIV