I'd like to +1 on the ideas for
- A kind of traceability system for both ends (buyers and vendors can see "Your thing is ordered", "Your thing has been made", "Your thing has been posted") and a simple bulk-adjustment thing for that. Cause that system would SUCK if you had to change one-by-one manually rather than "do these 20, select 20 in the thing, change to been made".
- Present the above stuff in a simple sheet? Something you could export to your preferred spreadsheet system of choice and use as your to-do-list if you're doing this across more than one platform.