Engineering Change Orders

[boottmills]

I am looking to reduce the number of Engineering Change Orders that we currently do. The way it works right now is that if there is any change to the print, then we need to ECO the print, even if it does not have anything to do with the form, fit, or function of the part.

What I am trying to propose is that if the change does not modify the form, fit, or function of the part then it should not be a ECO, but a Document Change. The document change will not change the revision of the drawing, but will change the version of the revision.

Is there anyone who is doing anything like this already, or has any ideas for doing this?

Boottmills

 

[mgard79]

According to ASMEY14.35M, "any change to a drawing after release, including a change to rights in data or security classification, requires the revision level to be advanced and shall be recorded in the Revision History block."

I've skirted this issue by keeping a folder of red-lined prints (with non-FFF changes), and holding them until they can be coupled with the next true revision. Depending on what specific changes you're talking about, this may be an option.

 

[boottmills]

mgard,

That is the wonderful (denote sarcasm) thing about working here!

The drawing/engineering standards used here are really our own and really do not fall under any standard that exists in the field. (GD&T went out the window for me as soon as I started working here).

So I may be on my own here!

Boottmills

 

[fcsuper]

Any change to a drawing for any reason should be tracked on the drawing. If you want to use a version of revision, you can, but it still needs to be denoted in the rev block. As such, our company uses dots when this occurs. So a revision table might be A, B, C.1, C.2, D, etc.

However, I would suggest the idea that the number of ECO's needs to be reduced is inhernently flawed. Paperwork to make a change is still just that, paperwork, regardless of what it is called. What is seems like you may be looking for is a signature matrix, where the number and types of signatures on the ECO can be reduced for particular types of changes. Just a suggestion.



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]

boottmills,

The usual standard is that you do not modify form, fit for function on a given part and its drawing, period. If the part is to be modified, you generate a new drawing.

You need to record all changes to a drawing. If nothing else, you are moving out onto a slippery slope in which my non-FFF[ ]change is your FFF[ ]change. For example, it may appear to me that an anodize finish on your aluminium part is equivalent to the present alodine finish. Surprise!

JHG

 

[MintJulep]

Something done at a former employer and several current vendors:

The "Change Request". aka the "ECNR" Engineering Change Notice Request.

Simply put, it is a request that may be initiated by anyone to make a change. It is a thing that may start the ECO process.

The magic is:

An approved ECNR has the power to change the configuration, but not the drawing. If drawing 123 rev b has an approved ECNR written against it than any parts 123 made must be made as if an ECO had been processed to revise the drawing to incorporate the changes noted as necessary on the ECNR

Ostensibly, the reasion d'etre for this is that it allows faster reaction when the need for a change is identified.

Of course, to avoid abuse there must be time limits, and limits on the number of open ECNRs on any given drawing.

Sloppy, but if your procedures allow it...

 

[KENAT]

Bootmills, to pick up on what drawoh says, it seems you're starting off non standard.

A revision of a drawing (in most systems such as asme) means that a part to the new rev is fully backward compatible and old rev parts are forward compatible - essentially the parts are fully interchangeable regardless of rev.

If you are changing form/fit/function then it should normally be a new part number.

Either way, both options will require an ECO of some type to record the change/detail the new release.

Now I have seen different classes of 'ECO', sometimes given different names, with differing levels of approvals. So a really minor change that doesn't require new tooling etc may only need a couple of signatories while a significant change needs a whole bunch of approvals down to the factory cat. However the drawing still got a revision change.

What are you really trying to do?

1. reduce number of ecos

2. reduce number of drawing revisions

3. reduce the time/effort required for ecos

Either way the idea of accumulating drawing changes per some variation on what mgard & mint say is a reasonable idea. It needs to be administered and not abused and you need a way to work 'not to drawing', i.e. incorporating changes in the part in production before revving the drawing, but it can reduce the effort taken on eco's & drawing changes. Note that the document allowing them to incorporate changes not yet on the drawing can be separate from the request for drawing change - this is how it was done in the UK.

Another thing is to group a number of changes to related items on one eco rather than having a separate ECO for each change - though this can have drawbacks.

The real killer for anything you do like your original idea is defining what does or doesn't need a full ECO/rev change. Many people have trouble deciding if it should be a rev or new PN without introducing a third option.

I'd look at other ways of streamlining your ECO process rather than having minor changes not require a rev change.

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