That is the fundamental question I have been trying to unravel Colorblind. I don't consider it off topic and thanks for asking. Kinda hoping other people pitch in to help me figure this out.
The answer I am finding so far has to do with when things change hands. Most companies maintain separate databases / ledgers and each time an item changes hands, the process of authentication and establish provenance starts anew. For a supply chain which apparently has had issues with counterfeit, I'm interested to see if blockchain can secure provenance.
I like to think their primary advantage comes in building trust or removing the need for it within a multi-touch point supply chain. Currently most businesses have their own versions of ledgers in their own db’s, and when transactions occur, a bunch of work has to happen on both sides before everybody agrees to transact - contrast that with blockchain where they both have an identical copy of the same immutable ledger, and you see that trust is not so much of an issue anymore.
Of course, if you get everyone in the supply chain to agree to share in a tracking solution provider (SAP, Oracle, IMB etc all have solutions), then the database seems to function in a similar manner, but then you are basically giving what may be important or classified information over to a 3rd party vendor.
A buddy a work sent me this today and these guys do a nice job of explaining the basics:
http://hyperledger-fabric.readthedocs.io/en/release/blockchain.html#why-is-a-blockchain-useful