What is the standard for deleting items in the parts list?

[draftsmandon]

Here's the question, if I delete an item in a BOM that is no longer needed, can I re-use this number for a different part even if this new part is not a replacement for the deleted part? I think this creates confusion but a coleague disagrees. I have always heard that this is poor practice, but I can't find anything in ASME Y14.35 that supports this. Am I just missing it, or is it mentioned somewhere else? How do others handle this?

Thanks in advance for your time and your help.

 

[ctopher]

It's been a while for me. I think I remember this way:
If it's no longer used, replace with "Removed" or "Deleted". If the old P/N is obsolete and replaced by a new p/n, use the new p/n.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 06/08
ctopher's home (updated Apr 30, 2008)

 

[ewh]

I think that would have to be covered by a company standard. Y14.35 (Revision of Engineering Drawings...)gives you the option of drawing lines thru the item or completely removing it from the BOM. Y14.34M (Associated Lists) goes on to specify that "Items that are relocated due to additions or deletions are not considered revised" which, to me anyway, means that the item number CAN be reused.
For a clear concise solution, consult the company DRM. If none exists, I would either draw lines through the item or, as Chris posts, remove it and put DELETED in its place. Less chance for mis-interpretation or creating problems with other documentation that may refer to the item numbers that way.

Believe it if you need it or leave it if you dare. - [small]Robert Hunter[/small]

 

[fcsuper]

It is safer to delete or crossout if you have that option. Work instructions may have item references that are missed on the drawing's revision. If the item number is reused, someone following work instructions may not notice. If you put delete or crossout, they will notice and flag it.

That said, this isn't an option for many of us in the PLM universe.

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group

 

[drawoh]

draftsmandon,

What CAD package are you using?

When I started to play with SolidWorks, I satisfied myself that crossing out BOM items was risky. If you transferred data to some software that does not understand Microsoft Office character formatting, the cross-outs are no longer present. At the time I played with it, SolidWorks' system for maintaining item numbers was not reliable.

I do not refer to item numbers in SolidWorks drawing notes. SolidWorks can automatically renumber the parts list. If the drawing view does not work for me, or it ceases to work due to some revision I have done, I delete it and make a new one. This takes minutes, and it destroys the old parts list.

I do not know about the other CAD packages, but some of the problems above are independant of CAD. I would focus on producing clear assembly drawings, and treat each version of the parts list as an independant document.

JHG

 

[draftsmandon]

drawoh,

We are using AutoCAD 2D currently. My question was more general drafting in nature. We are considering the leap to 3D modeling and are considering either Solidworks, or UGS NX. Are there any other concerns about this subject within a given CAD program? Is there a CAD package that handles the parts list any better than another?

 

[ewh]

What type of product are you going to use the CAD package for? I ask, because regardless of how they handle BOMs, you will be paying a premium for NX over SolidWorks. NX is more powerful in its surfacing capability, but SW is a very good package for the money, especially for more generic shapes.

Believe it if you need it or leave it if you dare. - [small]Robert Hunter[/small]

 

[draftsmandon]

We can actually get a network version of either one for free so the cost to us is not a question. Our company is part of a larger corporation that has network liscences to just about any program we want. We haven't made the plunge at this point only because of time constraints and production schedules, and compatibility with other on site programs. We're currently weighing which programs to switch to and how it will affect our drafting proceedures and our production schedules. Since the topic of which program we use was brought up in this context, I thought I would ask if any had an advantange over another.

 

[CheckerRon]

Since you are using AutoCad, crossing out PL line items is probably the best way. If you use separate Revision Records, you can use DELETED on the PL find number line since the RR has the history. FCSUPER's points above are good ones.

 

[KENAT]

Back in the UK we didn’t' re-use item numbers, in fact we would leave unused item# between each block of similar items, e.g. parts with drawings were items 1-5 nuts were 8-10, bolts 13-15, washers 18-19 etc [we ordered item lists by similar items] to allow for future revs. I can't recall though if we deleted them or crossed out.

'Dumb' parts list, where you're basically just typing in the info support this well. So with Autocad this is probably a good way to do it. In fact my last place did this with Solid Edge rather than use the parametric list, this was one of it’s advantages over Pro E in our context as it facilitated this more easily.

'Smart' or parametric parts lists as you get with Pro E, Solid Edge & apparently Solid Works don't seem to handle this as well. They tend to renumber items/balloons based on various settings, preferences etc.

Y14.100 D-8 has some info on 'find numbers' but doesn't really specify on whether they can be re-used at next rev.

ewh - I don't see parts lists explicitly dealt with in 14.5m-1997, were you just referring to 4.1 Revision Methods or am I missing something again?


KENAT, probably the least qualified checker you'll ever meet...

 

[ewh]

KENAT - I didn't refer to Y14.5, I referred to Y14.34M and Y14.35.

draftsmandon - if the expense is not an issue, I would recommend NX, as it is a hydrid modeler and gives the freedom of having several methods of modeling, sketches included. Sketch based packages are much more restrictive in that regard.
As for the parts lists, NX can be set up to line through deleted items. I have not seen it work, but the settings are there.

Believe it if you need it or leave it if you dare. - [small]Robert Hunter[/small]

 

[KENAT]

I meant 14.35, not sure what happened to the 5.

4.1 generally talks about deleting or crossing through information but doesn't explicitly mention parts lists that I can see.

KENAT, probably the least qualified checker you'll ever meet...

 

[drawoh]

draftsmandon,

SolidWorks, and I am sure all the other 3D CAD programs, handle parts lists "intelligently". This is very good and productive most of the time. Do not rush into 3D CAD. 3D CAD is not idiot resistant, and most of it can be made to not work. Definitely, talk to your production and ERP people and work out a type once, use everywhere strategy. You will be happy and efficient.

There is no way the CAD "intelligence" is going to conform exactly to your design and documentation process. If you are not flexible, it will not work.

JHG

 

[ewh]

KENAT,
Right you are... it is not explicitly stated, but implicitly, which can lead to disagreement over interpretation. That is one reason why I agree with lining the item out or replacing the item with "DELETED". A more important reason for not reusing the item number is downstream documentation, as has already been noted.

Believe it if you need it or leave it if you dare. - [small]Robert Hunter[/small]

 

[KENAT]

Yeah, it's kind of belt and braces (suspenders for US natives) though as the standards, 14.100 maybe or is it 14.24, say not to use item/find numbers on other documentation, that they only apply to that drawing or something like that.

The place that the auto renumbering on our CAD gets us is things like non associative notes or if we fudge some cabling by putting balloons on the schematic or something.

KENAT, probably the least qualified checker you'll ever meet...

 

[ewh]

Good luck getting those standards followed here! The only reason Y14.5 and related drawing standards are enforced is because any done on "my" CAD system have to go through me. As far as drawings done on the other CAD system, there are no standards (even though the drawing format specifies them) and are generally checked and approved by the originators. Work instructions and other procedures are another subject entirely.


Believe it if you need it or leave it if you dare. - [small]Robert Hunter[/small]

 

[KENAT]

Dont' get me started on work instructions.

KENAT, probably the least qualified checker you'll ever meet...