yang686526

'certs required' note on drawings
i'm getting requests to add a note to various drawings stating that certs (sometimes both material and process verification) be supplied along with parts. i am accustomed to putting this requirement on the p.o. but never on the drawing. the thing that i am concerned about is that the next problem will be a request to specify lot size or individual part certs and that will lead to serialization notes and before i'm finished i'll be writing an entire spec as a drawing note. many of these drawings would have to be extensively redrawn to fit all of this 'dialogue'. this brings me to what i would like to see as a solution: a 'required certs' spec which could be referenced by a short note on the drawings, like:
3. "certs required per spec#####.1.2, lot size per 3.4"
does this seem like a viable solution?
processes of this type should not be on drawings. certs belong with qa docs. you could have a separate eng doc, maybe a bom/pl, that can list it.
the only info listed on dwgs are info to make/build the part.
chris
solidworks 06 4.1/pdmworks 06
autocad 06
i have been in the quality game for many, many years including about 20 years of consulting and i would suggest that the drawing contain all the information (plan) this is required to make the part which may include material specifications, etc. but all relating to making an acceptable product.
i would not suggest that information that certs are required, required lot sizes, supplier inspection information to be submitted or must be an iso 9000 company, etc. be placed on the drawing.
all this information must be placed on the po. keep it there.
dave
i agree with the others here. the drawing is not the proper place for this information. it is much easier (and less expensive) to revise a po than it is a drawing.
agree with the others. i've normally seen it on the po or in a document referenced by the po.
i don't think i've ever seen the full requirements detailed on the drawings.
only once or maybe twice have i seen a document referenced by the drawing which contained this but normally that document also had other information that did help define the part as well.
if it’s literally the same requirements for all the parts, or they can be put in a reasonable number of categories, you may want to create a spec covering this which can be referenced by the po. although arguably raising this doc should be qa, purchasing or maybe manufacturing’s job by doing it yourself and giving it to them at least you’ll seem proactive/meeting them half way.
we specify 'certs required on our drawing when certs are required for special processes because supplier quality never sees the p.o. this way everyone knows that the material should be accompanied by the certifications.
john nabors
"against stupidity the very gods themselves contend in vain." - friedrich von schiller
twenty years from you will wish you had not put that note on your drawings. those types of requirements belong on quality or process documents or even stated the purchase order to the vender.
we manufacture some pumps for the seawolf program and on those drawings they list revisions to material specs. it's really hard to find material to old specs when a mill produces material to the latest revision to the material spec.
best regards,
heckler
sr. mechanical engineer
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never argue with an idiot. they'll bring you down to their level and beat you with experience every time.
i 100% agree with heckler. i also worked on seawolf and virginia ... and others.
chris
solidworks 06 5.1/pdmworks 06
autocad 06
i like the idea of putting cert specs on the drawing. letting the producer know that the material they choose to make a part from must be certified or that the process must be validated is necessary to the specifications of the part.
we put out a drawing and it tells the limits of what is acceptable, but what if during the manufacturing process an unforseen step they follow has a detrimental effect on the finished part. a drawing should not control every step in the manufacture. following an unacceptable step may lead to a part with unacceptable properties.
i like the idea of a cert spec, however, it must be a separate document which could be referenced by the drawing but revised independantly to accommodate relative changes.
robert
putting the specific material certification on a drawing, for example anodize iaw mil-a-8625, is different than saying that certs are required as part of your quality system and incoming receiving inspection.
definitely use astm, sae, or other certification when specifying a material, your vendor better have material that meets those certs, but as far as requiring certs to accompany incoming material is not to be mentioned on a drawing.
--scott
thanks for that concise explanation. i always advocate complete and clear callouts for material, dimension and critical process on a drawing. i just don't like sending 'notes' to a vendor that should be in a contract or p.o. i am making one pass through an entire group of drawings right now that will reference a revised qc spec that defines when certs are required based on a symbol that i am adding to material callouts, heat treating, critical dimesions etc. this way we will just put the symbol next to those characteristics that must be documented or certified.
these docs will become part of the deliverables as noted on the p.o.
thanks for all of your input - that's what makes this website such a great resource.