Best practice for "Test Operation" (or process code) system?

Hi,

Would anyone be willing to share (by link to blog or posting here) thoughts on best in class approaches to planning the list and number system for "Test Operations" in WATS?

We have come some way into our pilot phase but before we get too far and committed, I would like to try and get some learnings from the community on this subject. 

My thoughts so far is that you want "as few process codes" as possible, aiming for broader "groupings" than super-specific.  E.g. "Insulation Testing" used for all products that need to log a (single) insulation test, rather than "<product name> Insulation Test". Still, there could be cases where one would need multiple related process codes.  For example, some products may need several unique insulation tests done at different times in the production cycle, or perhaps a very specific type of insulation testing is done to meet a special product certification category where it would be beneficial to "tag" those in a separate process for grouping and reporting. 

At that point in my thinking, having only 10 numbers between categories seems like it could be too restrictive "in the future"?

Also, for our production, we have and will continue to have many "manual inspection" touch-points during production.  Since a SN# can only have one (active) pass-fail result per process code, and since the inspections by nature cannot be completed "all at once", this category in particular seems like it could be difficult to manage. .  My idea on that so far is to try to identify more exactly the unique "position in the production flows" where these inspections occur and try to group them that way and then end up with e.g. "Manual inspection - pre-stack", "Manual inspection - pre casting", "Manual inspection - post casting" etc. 

So maybe similar to WATS shipping concept, but multiplied out by 10 or 100 to allow more sub-categories within? pro-con to that approach? "1000 - Incomming Inspection", "2000 - First of Line Test", .... "10000 - End of Line Test" ...?

I am very curious to hear if anyone would be willing to share any ideas, wisdom, or experiences on this topic in general!