I might have to do something similiar but only on the item master. Key is make standard reports work as opposed to writing everything in crystal and simplify item understanding throughout the company.
For example: if anyone in company sees item number on picklist, bom or other starting with 12, they know it is corrugated product, they see 12008, they know it is box divider.
Same for Chemicals, they see 10, it is chemical, 10001 it is Dye in specific. This as opposed to seeing CF1003, CH2004 and ZZ232 like it is now for some chemicals.
I have already instituted item numbering sequences for creating NEW items but problem with converting existing to new number and inactivating old number is new number won't have history.
I went through and found all 300+ item master table references in all the tables under all names item number goes by (Itemcode, code, father, origitem, etc) and created SQL Script that would update them all from one number to another but I really didn't want to use it. So before even testing it out, I figured on asking the Community for help first. Glad I did since I haven't read Eula in years so it saves me testing.