The encyclopedia · Software & IT · Technical decision · 2018-2019
Walmart put leaf-greens supply chains on a shared blockchain
Walmart required leafy-green suppliers onto IBM Food Trust, cutting a food trace from about seven days to 2.2 seconds.
Walmart · IBM
the move
In 2018 a U.S. romaine E. coli outbreak was hard to contain, because tracing a bag of salad back to the farm could take days of filing and phone calls.
Walmart told its leafy-green suppliers they would have to put their data on IBM Food Trust, a permissioned blockchain built on Hyperledger Fabric, by September 2019.
Each node in the network is an entity that handled the food, so the transfer history becomes one shared record; in pilot work Walmart had already cut trace time from about seven days to 2.2 seconds.
IBM designed simple onboarding so a small grower could upload data from a phone without being a blockchain expert.
why it works
- A shared ledger removes the reconciliation between each company's own records.
- Immutable custody lets a batch be traced to a specific supplier rather than a broad risk area.
- Faster trace means contaminated produce is pulled before more of it reaches shoppers.
- Simple onboarding lets small farms participate without building new IT teams.
what transfers
Make the whole chain write to one record, and traceability stops being a hunt through silos.
what came after
Walmart expanded tracked products well beyond leafy greens and IBM Food Trust grew to hundreds of members, showing a shared digital record of custody; the wider industry still moved slowly toward one common standard.
references
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