I've been trying to get the Stihl parts better organized at work. We've got 2 large I think 9x8 metal cubby shelves, side by side for a total of 144 little cubbies. The way I'm tentatively going forward is to fill one whole thing of them up with carburetors - so far I have about 1/2 of one full of carbs. I'm not sure yet if that's a lot or not enough. Seems like a lot of tools eventually need the carb replaced so it's probably not too much of a gamble - I keep virtually all the 10 different 250 carbs in stock, for instance.
The other side has common parts in descending order: fuel filters, fuel lines, sprockets, drums, clutches, tank caps, springs, etc. Air filters will be hung up on corkboard, eventually. I'm also working on individually bagging and tagging every part (not carbs and other things that are already singled out, with part numbers on them) so when I need, say a fuel filter I grab a baggie with one that has the part #, sku and price for easy write up. Or if a customer needs one - bingo here ya go. And bulk rewind string is hung up on spindles with a tape measure, lighter and cutter right by them.
I don't quite have a good grip on it all yet - I feel like there's probably some common parts I need to keep in stock. For instance just got some pawls after someone came in asking for one. Nuts, bolts, washers, grommets, bulk hose, tensioner parts, various kinds of springs (throttle, rewind, etc). Even a few coils might not hurt to have.
What I really want to do is keep bins on my work bench with small, common stuff, gaskets, fuel filters and spark plugs for example but the head mech has kind of stonewalled me on that.