ERP deployments have a reputation for being expensive, failure-riddled, and generally unpleasant; but normally that discourages people from blindly insisting that the new system is accurate(if anything; it can be a real struggle to get enough trust in the new system to be allowed to turn the old system off).
Was this case one where there wasn’t really an old system; and a bunch of paranoid management convinced that the little people where skimming the till suddenly had numbers to look at where previously they’d just brooded darkly on fairly high level numbers and their own suspicions?
Did some madman put the people whose credibility depended on the system being delivered to spec in a position where they could manufacture that impression by accusing counterexamples of being criminals?
It was actually the other way around. The subpostmasters were no longer able to prove that they weren’t skimming the till. From the Computer Weekly explainer:
Almost immediately after the installation of Horizon at Post Office branches, there was an increase in the number of subpostmasters experiencing accounting shortfalls that they could not explain. Many had never previously experienced such shortfalls. Under the paper-based system, they could track back and find the cause. But not anymore.
And while the technology had changed, the contract between the Post Office and subpostmasters, who owned their own businesses but were agents for the Post Office, remained the same. It stated that any accounting shortfalls were the responsibility of the subpostmasters unless they could prove otherwise. But without the chain of evidence created by paper-based accounting methods, proving the losses were not their fault was near impossible for many.
The best/worst bit is, Fujitsu are still getting paid to run the Horizon system (which remains in place):
I predict it’s going to take a long time for this to all finish up, but at this point it’s finally well known enough that the PO/Fujitsu can’t hope to hide it any more.
The Post Office’s false claims did not stop the programme, but they did cause the BBC to delay the broadcast by several weeks.
Documents submitted to the ongoing public inquiry reveal how that small victory was celebrated by Post Office senior management. Then-chief executive Paula Vennells congratulated Mark Davies and his PR team on their “extensive work”.
