I generally agree with you and if I had to implement the solution, I wouldn't do so with blockchain.
That said, if there's a concern about data manipulation from Walmart's side (that is, employees erasing or modifying the data), blockchain would help with that.
If you look at blockchain as something almost like a cousin of PGP in the sense that you distribute signing operations it’s actually an interesting and novel technology.
Fundamentally, you could use clipboards and wet signatures to get the same result. That doesn’t mean that this approach is flawed.
Would we? That seems like a perfectly reasonable solution to me. You have a clear central authority here who could be issuing certificates to trusted third parties. It's a perfect fit for a CA and a bad fit for a blockchain.
Produce is more dynamic and 100% cost driven.
You have multiple, unsophisticated suppliers that shift based on season, weather, etc. These folks are located in the middle of nowhere in many cases and may or may not have connectivity.
Carting the produce from these suppliers to distribution is performed by any number of trucking companies. Then you have the huge distributed enterprise of WalMart itself, with dozens/hundreds of DCs and an internal fleet of trucks and contractors who cart products to the store.
Bitcoin demonstrated that a large number of unknown parties can successfully store and transfer value. I don't see why this would be a bad fit.
I mean what are you proposing exactly, that anybody can stuff a bunch of Lettuce in a truck, send it to Wallmart while generating a wallet address on WallmartCoin? Where's the traceability there exactly? What stops me from lying about the quality of my product or even who I am? What if I just wait for a farmer in my area to send a delivery of lettuce and impersonate them on the blockchain, how can it resolve the issue and figure out who did what? What if I buy cheap product from abroad and resell it as organic locally grown lettuce?
>Bitcoin demonstrated that a large number of unknown parties can successfully store and transfer value.
No, a large number of unknown parties can successfully transfer purely digital goods. As long as lettuce doesn't grow on the blockchain you'll need some kind of third party oracle to actually keep track of physical goods.
I know nothing about what is actually happening here, I'm speaking to a high-level process.
It seems logical that a workflow might look like this:
- All parties must have a supported application.
- Supplier scans carton labels as they are palletized and loaded into the truck. (you have a singed attestation that pallet x was loaded on truck y at location z)
- Truck is scanned on arrival at cross-dock.
- Cartons are scanned as they are loaded into various trucks for delivery. (you know how long the cold-chain was broken for perishables and who supplied what store)
- Cartons are scanned on arrival and scanned when shelved.
- Cartons are scanned when pulled and stocked.
The problem that you are solving is that at every step of the process, the process is at least partially out of Wal-Mart's control and every contractor has an incentive to either not track things or lie. If there is an e. coli outbreak, WalMart may destroy $5M of lettuce from Arizona where in reality they only needed to destroy $500k of lettuce from farmer X.
Is it the best solution? I have no idea.
When you get to the heart of things, that's all blockchain is anyway. The "blockchain" part really just describes how it's organized - in a signed chain
I also wonder how efficient it is to “query the block chain”?