Their prior database lacked transparency, real-time tracking, & scalability making tracing take days.
Just an FYI, Hyperledger Fabric is not like the blockchains for craptocurrency. It’s a highly modular, permissioned not permissionless, distributed ledger & it allows for pluggable consensus mechanisms. It’s very likely that Walmart uses a custom consensus algorithm and nothing like any of the public PoW, PoS, or PoA consensus algorithms.