Electronic parts distributors used to sell a similar service, running semiconductor parts through test stations and sorting them based on an extra narrow range of a measurable parameter.

They used automated test stations, so could do the sorting rapidly after setting up.
They did charge for the added handling and setup.

The point I was trying to make is that you shouldn't do the measuring, sorting, and segregation of inventory for free, especially if you are doing it all manually. You need to pay, er, Manuel.


Second, not having a unique part number for that customer's unique part is the edge of a slippery slope.
For small informal operations, you might tag the parts and/or packages with a paint pen spot or similar marking in addition to your normal marking. That should be sufficiently 'the same' so that the customer won't consider it a new part number.

... but your own people need to recognize the marking as special, so you have to document it.
How you do that depends on how large, and how organized, your outfit is.

Mike Halloran
Pembroke Pines, FL, USA

Suggestion 1: Find new customers so you don't need to cover for this one. It seems to me they are perpetrating a fraud somewhere by making a design change and trying to cover it up. I don't believe they would have to requalify based on a narrower spec than their original qualification allowed, but they apparently don't want to alert anyone that their product depends on a narrower spec item to function correctly. This is what GM did when they changed the spring on their ignition switches and didn't change the part number to match. There was also a TV maker who selected vacuum tubes so that the design could eliminate the need for other corrective circuits. It had the side effect that the casual repair was impossible, so any service had to use tubes from the manufacturer.

Suggestion 2: Add a MFR P/N that is the base number (their cage code?) plus their P.O. number. Without knowing what the part is, it's hard to tell how that could happen. Laser etch, rubber stamp, temporary tag, marked box if your workers won't foul it up. I suppose one could reduce it to a unobtrusive paint dot. It is possible they will change their minds and tying the parts to a P.O. will prevent them coming back later with earlier parts and saying they aren't suitable.

In real life these are dealt with using a Selected Item Drawing, as noted on slides 16-18 of http://www.dtic.mil/ndia/2008/technical/GastonEngi... and entails removal of the original id marking and application of unique/new id marking.

Keep existing p/n for 9-11 parts
Set up new p/n for 8-12 parts
Existing inventory needs to be sorted and restocked
Only order existing p/n from your supplier and sort and stock the required number of 9-11 for your PIA customer, re label the balance for other customers 8-12