Just wondering how some others decide whether to add a revision to a part of assign a new part number?
Assuming the form/fit/function matches…
I tend to favor revision on purchased parts, part materials (BOM items) and manufactured part numbers.
And where form/fit/function is suspect or I really need to track differences, I’ll tend to use new part numbers.
Just curious since in past discussions, the talks have turned a little “religious”.
I agree with your logic. Part numbers are cheap, so I would not be religious about it. But when you change part numbers versus revisions, you lose historical data such as sales and usage. Having spent most of my career in materials management, historical data is important.
We assign new Part numbers since you cannot stock more than once revision of a Part at a time. When we revise a Part, we may need to sell off the remaining qty of the original while beginning to produce the new revision. Epicor doesn’t allow for that.
In a previous life I worked for a company that worked in aerospace in defence, all of our revisions were part of the part number. we then used the revision for the planning revision.
we had to put the revision number in the part number to identify them as a different part, as we often supplied customers with older versions of aircraft.
Historical data is easy enough with a good dashboard, this is the way I suggest my customers handle it.
We use revision number, when a part changes, due exactly to historical data.
I was wandering what was the idea behind not following the revisions numbers in inventory. Revisions are used everywhere else ! The only way toestablish this is to use lot numbers ! We only use lot numbers for a few important parts the rest is not using it.
If you want to phase out a rev number in stock, the knowledge of how many are in stock is unavailable…
At my previous company (an Aerospace Machine Shop), we created a BPM to add the “_RevLetter” to the lot number as it was put into inventory to get the revision traceability to the lot. We did not want to use revisions with part numbers due to losing history and making it more difficult to up-rev parts when drawings update the rev with minor not changes.
Avoid Sacred Cows. And whatever you decide, it will be your Cross to Bear 
At one site I used to work, the choice between Rev and new PN was partly based on process problems in manufacturing. Parts were stocked in a bin by part number only - no tagging/marking to indicate the revision. So in some cases engineers would assign new part numbers for better control, depending on how critical a design change might be.
Even that wasn’t 100% - I would still find old components in new job assemblies when I took the time to go out and check.