Definition Rework - Definition

Rework: Defined as action that returns the object back to drawing specifications. Does not require customer approval.

Elsmar Cove Rework discussion threads.

EDIT: Obsolete link replaced.

Elsmar Cove Wiki: Rework.

I would question the 'Does not require customer approval' statement. Although this may (generally) be true, there may be exceptions to that.

Eg. Parts are electroplated and are stored in WIP for a period of 45 days. Prior to shipment, dock audit detects that the surface roughness of the parts is unacceptable.

In consultation with the coating supplier, it is determined that parts need to be stripped and replated.

Strip method is to acid wash, followed by 'burn', followed by wash, followed by re-plate and reinspect.

Parts are SAE4130, hardened to HRc 38-44. There is a potential risk for the following failures:
i) Hydrogen embrittlement (yeah, I know, but they raised that one one me)
ii) Tempering of hardness to below the lower limit (hardness is an SC)
iii) Pitting of part surface, leading to stress risers (this one is a REAL stretch on the part of the design engineer, but I don't have the knowledge to refute it).

The reasons above (if nothing else) are sufficient cause to notify the customer of your 'rework' process, and obtain acquiesence, if not outright approval.

JMO

Ron,

You raise an excellent point. I have been in situations where bad things happened because of exactly the sort of metallurgical phenomena you describe. Speaking from a customer standpoint, I want to know when rework is going on for this type of reason, but also because if it gets to be a habit, sooner or later I'm going to pay for it. Realistically, suppliers aren't going to notify customers when they've screwed up, especially if they think that they can rework material without causing any problems for the customer. But as this case shows, there are times when the supplier may lack the expertise or general knowledge to know when what seems to be innocuous rework can cause problems. The solution? A contractual obligation for the supplier to divulge. That won't cause the supplier to divulge in every instance, but it does provide a measure of liability protection if something goes wrong.

Also see this thread: Definition of Repair

EDIT: LINK UPDATED.

rework vs. repair

Ron Rompen said:

I would question the 'Does not require customer approval' statement. Although this may (generally) be true, there may be exceptions to that.

Eg. Parts are electroplated and are stored in WIP for a period of 45 days. Prior to shipment, dock audit detects that the surface roughness of the parts is unacceptable.

In consultation with the coating supplier, it is determined that parts need to be stripped and replated.

Strip method is to acid wash, followed by 'burn', followed by wash, followed by re-plate and reinspect.

Parts are SAE4130, hardened to HRc 38-44. There is a potential risk for the following failures:
i) Hydrogen embrittlement (yeah, I know, but they raised that one one me)
ii) Tempering of hardness to below the lower limit (hardness is an SC)
iii) Pitting of part surface, leading to stress risers (this one is a REAL stretch on the part of the design engineer, but I don't have the knowledge to refute it).

The reasons above (if nothing else) are sufficient cause to notify the customer of your 'rework' process, and obtain acquiesence, if not outright approval.

JMO

Click to expand...

Ron,
Your example is exactly why the rework/repair and/or MRB authority is negotiated upfront with the customer. I doubt that the original specification for the plate called for an acid wash to strip. This very act would classify this as a repair not a rework (imo) and so would require customer approval.

Again, imo, (from many years on MRB) these kind of situations were exactly why MRB was composed of a cross section of talent including design engineering, quality engineering and yes in many cases the customer. It helped prevent the declaration of rework in the face of a repair.

I might add that some WS (weapon specifications) for soldering considered the act of reflowing a solder joint on a PCB a repair where MIL-S solder specs considered this to be rework. The WS's position was that the very act of putting heat to the solder joint could very well degrade the fiberglass board material. Under the WS a simple solder touch up was often referred to MRB. In another version of WS when solder joint touch ups surpassed three the PCB was then sent to MRB for disposition. Again all pre-negotiated with the Customer.

All are excellent points. We also do aviation work governed by the FAA here at our facility. Rework / repair all have to be approved according to the original design (which always includes the blueprint dimensions and how the part or component is made). A non-conforming part (at any stage of manufacture) is dispositioned in the MRB and any rework or repair must follow a specific, pre-approved procedure (if allowed at all). If rework is done without approval the part or parts are quarantined until the customer (FAA or other) approves the rework or repair procedure.

Why so stringent? The answer is simple. No one wants to be asked to explain a smoking hole in the ground when a airplane crashes due to your rework or repair procedure.

Jim Howe said:

This very act would classify this as a repair not a rework (imo) and so would require customer approval.

Click to expand...

Agree, this is a repair, not a rework.

Hi
I have a question regarding rework or reprocess. When we want to remove the wrong labels and replace it with correct one, is it considered as rework or reprocess?
we will do the same steps for printing out and attaching labels but what about removing the wrong labels?
Thank you.

shala said:

Hi
I have a question regarding rework or reprocess. When we want to remove the wrong labels and replace it with correct one, is it considered as rework or reprocess?
we will do the same steps for printing out and attaching labels but what about removing the wrong labels?
Thank you.

Click to expand...

Hi Shala,
When I need to do this I use the term "rework" in my records.

Hi, shala:
I suppose it really depends on what exactly encompasses your "relabeling" process. If it's as simple as peeling off one label and applying another, calling it rework would be just fine. If it's a more involved process, requiring assertive cleaning or scraping which might potentially harm the product, then the answer is no longer a basic issue of semantics.

As for using the word "reprocess," that almost always insinuates the reapplication of some special process (e.g. heat treating), so this probably wouldn't be the best use for that word.