repair part change of purchased interchangeable item 1

If fit, form, and function have not changed, I would not change P/Ns.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

Agree, part number does not need to change.

Mike

Fit, Form & Function are only a subset of the requirements for keeping the same part number.

ASME y14.100 gives more detail but in essence, if the part is completely interchangeable, and there is not need to track the differences then it can be the same PN.

Differences may be to do with traceability or other paperwork rather than more obvious physical differences.

I'm not quite clear whats going on from the OP. The 'repair parts' are different - how so?

What do yo mean by 'repair parts'? Are these replacement parts being sent out to repair items in the field? Or are they actually refurbished parts?

It's sometimes necessary to track refurbished parts, such as if they may be expected to have a lower life or something, and in such cases they may require a separate PN.

Sorry Kenat, I should have been clearer,
We used to buy a standardized electric motor from supplier X to be used in our electric pumps. We have changed to supplier Y.
Now we want to supply to our customers the replacement parts of the motor.
The problem is that these parts differ from supplier X to Y. We have changed the configuration of the pump in order to identify the right parts but I have some doubts about changing the p/n of the motor itself.

As per ASME Y14.100-2004 I had read paragraph 6.8.1 but now have found a different wording on appendix D.

Any thoughts?

ASME Y14.100-2004 said:

D-13 Change Requiring New Identification When a repair part within an item is changed so that it is no longer interchangeable with its previous version, it shall be assigned a new PIN. A new PIN shall also be assigned to the next higher assembly for the changed repair part and to all subsequent higher assemblies up to and including the level at which interchangeability is re-established. The design or procuring activity shall assign new PINs when a part or item is changed in such a manner that any of the following conditions occur:
(a) Condition 1. Performance or durability is affected to such an extent that superseded items must be discarded or modified for reasons of safety or malfunction.
(b) Condition 2. Parts, subassemblies, or complete articles are changed to such an extent that the superseded and superseding items are not interchangeable.
(c) Condition 3. When superseded parts are limited to use in specific articles or models of articles and the superseding parts are not so limited to use.
(d) Condition 4. When an item has been altered, selected, or is a source control item. See ASME Y14.24.

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OK, so you're actually talking about replacing sub components of the motor if I understand you.

The overall motor is interchangeable for your purposes, but repair components of the motor are not.

In this case I'd say you need to be able to differentiate between the 2 motors because of the repair part implications.

To some extent you've already achieved this by changing the designation of the assy's where the motors get used. What I don't see is how you can confirm this configuration if the motor has the same PN.

I'm tempted to err on the side of caution then and assign a different PN for the motor to help traceability. With hindsight this perhaps should have been done when the change was made originally all it now seems a potential mess whatever you do.

Your current setup is that the motor part number refers to different motors that can be swapped as a whole motor with no problems. If something goes wrong with an older assembly that requires the motor to be replaced, you could send either motor depending on what is in stock. Over time you would have no way to be sure what motor is used with what assembly without very good record keeping, not easy if the part number is the same.

If a customer needs to replace a part of the motor, you would need to either have very good records of what motor is in a particular unit, or have the customer (or a service rep) determine what motor he has. You may have customers with some of each and he may not know that he is asking for the wrong replacement part.

I would recommend you change the part number of the new motor now. There will still be units in the field using a motor part number that has two versions, but you would not be adding to the problem. The new motor part would be the replacement for the old motor part when replaced as a whole. Am I correct in thinking that in the past you replaced the motor as a whole instead of supplying component parts of the motor?

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

Hi Peter,
You are right, in the past we replaced the motor as a whole, we did not supply component parts of the motor.

Thank you for your insights