Just my 2 cents, since the OP was mentioning "Inventory software" - the inventory aspects of RepairShopr have changed a lot in the last year.
The inventory is now fully serialized for maintain stock products - and you can optionally track "serial numbers" too.
http://feedback.repairshopr.com/kno...2782-can-i-add-serial-numbers-to-my-inventory
This means - beyond tracking "counts" like QuickBooks or some other basic inventory systems - RepairShopr has a robust inventory system that will track the life of a single instance of a product forever. From the Purchase Order it came in on, the cost, the date, the vendor - that data is stored and a label can be printed from the Purchase Order that carries that data with it.
Once this item is sold, if it ever comes back you can find the invoice - and find the detailed history of that instance.
Lots of shops use this to track bad batches, and to be able to RMA a generic product back to the correct vendor.
Maybe you buy Kingston ram from amazon, and Ingram - and they look identical physically. With the serialized inventory when you do a return/RMA on that line item - it knows which vendor it came from and you can see it easily.
This is the closest thing to an ERP-type inventory system without being in an ERP - quite sure it's the strongest inventory system you can find "in a ticketing system".
I know none of this matters much to many small shops - in my repair shop I never tracked this closely - but it does matter to the hundreds of people that kept giving feedback saying we needed to improve the inventory!