It seems the answer here is that, yes the supply chain may be long enough for untrustworthy entities to be part of it somewhere.
A regular database would be great if it was just farmer sells to Walmart and Walmart maintains the database that tracks it all.
It looks like the block-chain solution is the way to create that good chain-of-custody data. Especially when not all the parties have direct contact or even any direct business relationship.
I went back to read the article (stunning I know). Right at the top, it has this statement: “direct suppliers of lettuce, spinach and other greens to join its food-tracking blockchain by Jan. 31. The retailer also will mandate that farmers, logistics firms and business partners of these suppliers join the blockchain”
It looks like Walmart deals with direct suppliers. Those direct suppliers may deal with logistics companies or other indirect suppliers, and somewhere down at the bottom is a farmer. I can easily picture a bunch of farmers selling to a logistics company that sells to one or many processors, that in turn sell to Walmart. Where the farmer grows and harvests, but then hands off for transport. The transporter specializes in just moving from farm to processor. Then a processor that sorts, cleans and packages. Finally sold to Walmart who ships it to stores themselves.
In this scenario, from the story it sounds like the goal is for a farmer to make and entry about what’s delivered to transporter, the transporter to make an entry about the aggregation of farms and delivery to the processor, the processor to enter updates about how it’s processed and moved on to Walmart then. Today, the farmer may not even know their stuff is going to Walmart at all. With the mandate to make the block chain entry, they’ll know that at least some is going to Walmart, since that’s where the mandate is originating. Presumably, others that could take delivery at any of those steps could use the information too.
I’m usually super sceptical about anytime block chain is suggested to fix something. But, this one, with all the disconnected parties involved that all want a record, sounds like a good fit. Then again, some big player could just become the “master database in the cloud” and provide the same function as a trusted registry for all the data.
I’m guessing today it’s all done disconnected from each other between each direct party only, some of them probably only on paper. That’s why it takes so long to track back. An investigator needs to go to each step one at a time and trace it back. This solution, or the central database, would both help with the tracking speed.
